/****************************************************************************** * * Copyright(c) 2003 - 2011 Intel Corporation. All rights reserved. * * Portions of this file are derived from the ipw3945 project, as well * as portions of the ieee80211 subsystem header files. * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2 of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA * * The full GNU General Public License is included in this distribution in the * file called LICENSE. * * Contact Information: * Intel Linux Wireless * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 * *****************************************************************************/ #include #include #include /*TODO: Remove include to iwl-core.h*/ #include "iwl-core.h" #include "iwl-io.h" #include "iwl-trans-pcie-int.h" /****************************************************************************** * * RX path functions * ******************************************************************************/ /* * Rx theory of operation * * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs), * each of which point to Receive Buffers to be filled by the NIC. These get * used not only for Rx frames, but for any command response or notification * from the NIC. The driver and NIC manage the Rx buffers by means * of indexes into the circular buffer. * * Rx Queue Indexes * The host/firmware share two index registers for managing the Rx buffers. * * The READ index maps to the first position that the firmware may be writing * to -- the driver can read up to (but not including) this position and get * good data. * The READ index is managed by the firmware once the card is enabled. * * The WRITE index maps to the last position the driver has read from -- the * position preceding WRITE is the last slot the firmware can place a packet. * * The queue is empty (no good data) if WRITE = READ - 1, and is full if * WRITE = READ. * * During initialization, the host sets up the READ queue position to the first * INDEX position, and WRITE to the last (READ - 1 wrapped) * * When the firmware places a packet in a buffer, it will advance the READ index * and fire the RX interrupt. The driver can then query the READ index and * process as many packets as possible, moving the WRITE index forward as it * resets the Rx queue buffers with new memory. * * The management in the driver is as follows: * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled * to replenish the iwl->rxq->rx_free. * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the * iwl->rxq is replenished and the READ INDEX is updated (updating the * 'processed' and 'read' driver indexes as well) * + A received packet is processed and handed to the kernel network stack, * detached from the iwl->rxq. The driver 'processed' index is updated. * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free * list. If there are no allocated buffers in iwl->rxq->rx_free, the READ * INDEX is not incremented and iwl->status(RX_STALLED) is set. If there * were enough free buffers and RX_STALLED is set it is cleared. * * * Driver sequence: * * iwl_rx_queue_alloc() Allocates rx_free * iwl_rx_replenish() Replenishes rx_free list from rx_used, and calls * iwl_rx_queue_restock * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx * queue, updates firmware pointers, and updates * the WRITE index. If insufficient rx_free buffers * are available, schedules iwl_rx_replenish * * -- enable interrupts -- * ISR - iwl_rx() Detach iwl_rx_mem_buffers from pool up to the * READ INDEX, detaching the SKB from the pool. * Moves the packet buffer from queue to rx_used. * Calls iwl_rx_queue_restock to refill any empty * slots. * ... * */ /** * iwl_rx_queue_space - Return number of free slots available in queue. */ static int iwl_rx_queue_space(const struct iwl_rx_queue *q) { int s = q->read - q->write; if (s <= 0) s += RX_QUEUE_SIZE; /* keep some buffer to not confuse full and empty queue */ s -= 2; if (s < 0) s = 0; return s; } /** * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue */ void iwl_rx_queue_update_write_ptr(struct iwl_trans *trans, struct iwl_rx_queue *q) { unsigned long flags; u32 reg; spin_lock_irqsave(&q->lock, flags); if (q->need_update == 0) goto exit_unlock; if (hw_params(trans).shadow_reg_enable) { /* shadow register enabled */ /* Device expects a multiple of 8 */ q->write_actual = (q->write & ~0x7); iwl_write32(bus(trans), FH_RSCSR_CHNL0_WPTR, q->write_actual); } else { /* If power-saving is in use, make sure device is awake */ if (test_bit(STATUS_POWER_PMI, &trans->shrd->status)) { reg = iwl_read32(bus(trans), CSR_UCODE_DRV_GP1); if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) { IWL_DEBUG_INFO(trans, "Rx queue requesting wakeup," " GP1 = 0x%x\n", reg); iwl_set_bit(bus(trans), CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ); goto exit_unlock; } q->write_actual = (q->write & ~0x7); iwl_write_direct32(bus(trans), FH_RSCSR_CHNL0_WPTR, q->write_actual); /* Else device is assumed to be awake */ } else { /* Device expects a multiple of 8 */ q->write_actual = (q->write & ~0x7); iwl_write_direct32(bus(trans), FH_RSCSR_CHNL0_WPTR, q->write_actual); } } q->need_update = 0; exit_unlock: spin_unlock_irqrestore(&q->lock, flags); } /** * iwlagn_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr */ static inline __le32 iwlagn_dma_addr2rbd_ptr(dma_addr_t dma_addr) { return cpu_to_le32((u32)(dma_addr >> 8)); } /** * iwlagn_rx_queue_restock - refill RX queue from pre-allocated pool * * If there are slots in the RX queue that need to be restocked, * and we have free pre-allocated buffers, fill the ranks as much * as we can, pulling from rx_free. * * This moves the 'write' index forward to catch up with 'processed', and * also updates the memory address in the firmware to reference the new * target buffer. */ static void iwlagn_rx_queue_restock(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rx_queue *rxq = &trans_pcie->rxq; struct list_head *element; struct iwl_rx_mem_buffer *rxb; unsigned long flags; spin_lock_irqsave(&rxq->lock, flags); while ((iwl_rx_queue_space(rxq) > 0) && (rxq->free_count)) { /* The overwritten rxb must be a used one */ rxb = rxq->queue[rxq->write]; BUG_ON(rxb && rxb->page); /* Get next free Rx buffer, remove from free list */ element = rxq->rx_free.next; rxb = list_entry(element, struct iwl_rx_mem_buffer, list); list_del(element); /* Point to Rx buffer via next RBD in circular buffer */ rxq->bd[rxq->write] = iwlagn_dma_addr2rbd_ptr(rxb->page_dma); rxq->queue[rxq->write] = rxb; rxq->write = (rxq->write + 1) & RX_QUEUE_MASK; rxq->free_count--; } spin_unlock_irqrestore(&rxq->lock, flags); /* If the pre-allocated buffer pool is dropping low, schedule to * refill it */ if (rxq->free_count <= RX_LOW_WATERMARK) queue_work(trans->shrd->workqueue, &trans_pcie->rx_replenish); /* If we've added more space for the firmware to place data, tell it. * Increment device's write pointer in multiples of 8. */ if (rxq->write_actual != (rxq->write & ~0x7)) { spin_lock_irqsave(&rxq->lock, flags); rxq->need_update = 1; spin_unlock_irqrestore(&rxq->lock, flags); iwl_rx_queue_update_write_ptr(trans, rxq); } } /** * iwlagn_rx_replenish - Move all used packet from rx_used to rx_free * * When moving to rx_free an SKB is allocated for the slot. * * Also restock the Rx queue via iwl_rx_queue_restock. * This is called as a scheduled work item (except for during initialization) */ static void iwlagn_rx_allocate(struct iwl_trans *trans, gfp_t priority) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rx_queue *rxq = &trans_pcie->rxq; struct list_head *element; struct iwl_rx_mem_buffer *rxb; struct page *page; unsigned long flags; gfp_t gfp_mask = priority; while (1) { spin_lock_irqsave(&rxq->lock, flags); if (list_empty(&rxq->rx_used)) { spin_unlock_irqrestore(&rxq->lock, flags); return; } spin_unlock_irqrestore(&rxq->lock, flags); if (rxq->free_count > RX_LOW_WATERMARK) gfp_mask |= __GFP_NOWARN; if (hw_params(trans).rx_page_order > 0) gfp_mask |= __GFP_COMP; /* Alloc a new receive buffer */ page = alloc_pages(gfp_mask, hw_params(trans).rx_page_order); if (!page) { if (net_ratelimit()) IWL_DEBUG_INFO(trans, "alloc_pages failed, " "order: %d\n", hw_params(trans).rx_page_order); if ((rxq->free_count <= RX_LOW_WATERMARK) && net_ratelimit()) IWL_CRIT(trans, "Failed to alloc_pages with %s." "Only %u free buffers remaining.\n", priority == GFP_ATOMIC ? "GFP_ATOMIC" : "GFP_KERNEL", rxq->free_count); /* We don't reschedule replenish work here -- we will * call the restock method and if it still needs * more buffers it will schedule replenish */ return; } spin_lock_irqsave(&rxq->lock, flags); if (list_empty(&rxq->rx_used)) { spin_unlock_irqrestore(&rxq->lock, flags); __free_pages(page, hw_params(trans).rx_page_order); return; } element = rxq->rx_used.next; rxb = list_entry(element, struct iwl_rx_mem_buffer, list); list_del(element); spin_unlock_irqrestore(&rxq->lock, flags); BUG_ON(rxb->page); rxb->page = page; /* Get physical address of the RB */ rxb->page_dma = dma_map_page(bus(trans)->dev, page, 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); /* dma address must be no more than 36 bits */ BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36)); /* and also 256 byte aligned! */ BUG_ON(rxb->page_dma & DMA_BIT_MASK(8)); spin_lock_irqsave(&rxq->lock, flags); list_add_tail(&rxb->list, &rxq->rx_free); rxq->free_count++; spin_unlock_irqrestore(&rxq->lock, flags); } } void iwlagn_rx_replenish(struct iwl_trans *trans) { unsigned long flags; iwlagn_rx_allocate(trans, GFP_KERNEL); spin_lock_irqsave(&trans->shrd->lock, flags); iwlagn_rx_queue_restock(trans); spin_unlock_irqrestore(&trans->shrd->lock, flags); } static void iwlagn_rx_replenish_now(struct iwl_trans *trans) { iwlagn_rx_allocate(trans, GFP_ATOMIC); iwlagn_rx_queue_restock(trans); } void iwl_bg_rx_replenish(struct work_struct *data) { struct iwl_trans_pcie *trans_pcie = container_of(data, struct iwl_trans_pcie, rx_replenish); struct iwl_trans *trans = trans_pcie->trans; if (test_bit(STATUS_EXIT_PENDING, &trans->shrd->status)) return; mutex_lock(&trans->shrd->mutex); iwlagn_rx_replenish(trans); mutex_unlock(&trans->shrd->mutex); } /** * iwl_rx_handle - Main entry function for receiving responses from uCode * * Uses the priv->rx_handlers callback function array to invoke * the appropriate handlers, including command responses, * frame-received notifications, and other notifications. */ static void iwl_rx_handle(struct iwl_trans *trans) { struct iwl_rx_mem_buffer *rxb; struct iwl_rx_packet *pkt; struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rx_queue *rxq = &trans_pcie->rxq; struct iwl_tx_queue *txq = &trans_pcie->txq[trans->shrd->cmd_queue]; struct iwl_device_cmd *cmd; u32 r, i; int reclaim; unsigned long flags; u8 fill_rx = 0; u32 count = 8; int total_empty; int index, cmd_index; /* uCode's read index (stored in shared DRAM) indicates the last Rx * buffer that the driver may process (last buffer filled by ucode). */ r = le16_to_cpu(rxq->rb_stts->closed_rb_num) & 0x0FFF; i = rxq->read; /* Rx interrupt, but nothing sent from uCode */ if (i == r) IWL_DEBUG_RX(trans, "r = %d, i = %d\n", r, i); /* calculate total frames need to be restock after handling RX */ total_empty = r - rxq->write_actual; if (total_empty < 0) total_empty += RX_QUEUE_SIZE; if (total_empty > (RX_QUEUE_SIZE / 2)) fill_rx = 1; while (i != r) { int len, err; u16 sequence; rxb = rxq->queue[i]; /* If an RXB doesn't have a Rx queue slot associated with it, * then a bug has been introduced in the queue refilling * routines -- catch it here */ if (WARN_ON(rxb == NULL)) { i = (i + 1) & RX_QUEUE_MASK; continue; } rxq->queue[i] = NULL; dma_unmap_page(bus(trans)->dev, rxb->page_dma, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); pkt = rxb_addr(rxb); IWL_DEBUG_RX(trans, "r = %d, i = %d, %s, 0x%02x\n", r, i, get_cmd_string(pkt->hdr.cmd), pkt->hdr.cmd); len = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK; len += sizeof(u32); /* account for status word */ trace_iwlwifi_dev_rx(priv(trans), pkt, len); /* Reclaim a command buffer only if this packet is a response * to a (driver-originated) command. * If the packet (e.g. Rx frame) originated from uCode, * there is no command buffer to reclaim. * Ucode should set SEQ_RX_FRAME bit if ucode-originated, * but apparently a few don't get set; catch them here. */ reclaim = !(pkt->hdr.sequence & SEQ_RX_FRAME) && (pkt->hdr.cmd != REPLY_RX_PHY_CMD) && (pkt->hdr.cmd != REPLY_RX) && (pkt->hdr.cmd != REPLY_RX_MPDU_CMD) && (pkt->hdr.cmd != REPLY_COMPRESSED_BA) && (pkt->hdr.cmd != STATISTICS_NOTIFICATION) && (pkt->hdr.cmd != REPLY_TX); sequence = le16_to_cpu(pkt->hdr.sequence); index = SEQ_TO_INDEX(sequence); cmd_index = get_cmd_index(&txq->q, index); if (reclaim) cmd = txq->cmd[cmd_index]; else cmd = NULL; /* warn if this is cmd response / notification and the uCode * didn't set the SEQ_RX_FRAME for a frame that is * uCode-originated * If you saw this code after the second half of 2012, then * please remove it */ WARN(pkt->hdr.cmd != REPLY_TX && reclaim == false && (!(pkt->hdr.sequence & SEQ_RX_FRAME)), "reclaim is false, SEQ_RX_FRAME unset: %s\n", get_cmd_string(pkt->hdr.cmd)); err = iwl_rx_dispatch(priv(trans), rxb, cmd); /* * XXX: After here, we should always check rxb->page * against NULL before touching it or its virtual * memory (pkt). Because some rx_handler might have * already taken or freed the pages. */ if (reclaim) { /* Invoke any callbacks, transfer the buffer to caller, * and fire off the (possibly) blocking * iwl_trans_send_cmd() * as we reclaim the driver command queue */ if (rxb->page) iwl_tx_cmd_complete(trans, rxb, err); else IWL_WARN(trans, "Claim null rxb?\n"); } /* Reuse the page if possible. For notification packets and * SKBs that fail to Rx correctly, add them back into the * rx_free list for reuse later. */ spin_lock_irqsave(&rxq->lock, flags); if (rxb->page != NULL) { rxb->page_dma = dma_map_page(bus(trans)->dev, rxb->page, 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); list_add_tail(&rxb->list, &rxq->rx_free); rxq->free_count++; } else list_add_tail(&rxb->list, &rxq->rx_used); spin_unlock_irqrestore(&rxq->lock, flags); i = (i + 1) & RX_QUEUE_MASK; /* If there are a lot of unused frames, * restock the Rx queue so ucode wont assert. */ if (fill_rx) { count++; if (count >= 8) { rxq->read = i; iwlagn_rx_replenish_now(trans); count = 0; } } } /* Backtrack one entry */ rxq->read = i; if (fill_rx) iwlagn_rx_replenish_now(trans); else iwlagn_rx_queue_restock(trans); } static const char * const desc_lookup_text[] = { "OK", "FAIL", "BAD_PARAM", "BAD_CHECKSUM", "NMI_INTERRUPT_WDG", "SYSASSERT", "FATAL_ERROR", "BAD_COMMAND", "HW_ERROR_TUNE_LOCK", "HW_ERROR_TEMPERATURE", "ILLEGAL_CHAN_FREQ", "VCC_NOT_STABLE", "FH_ERROR", "NMI_INTERRUPT_HOST", "NMI_INTERRUPT_ACTION_PT", "NMI_INTERRUPT_UNKNOWN", "UCODE_VERSION_MISMATCH", "HW_ERROR_ABS_LOCK", "HW_ERROR_CAL_LOCK_FAIL", "NMI_INTERRUPT_INST_ACTION_PT", "NMI_INTERRUPT_DATA_ACTION_PT", "NMI_TRM_HW_ER", "NMI_INTERRUPT_TRM", "NMI_INTERRUPT_BREAK_POINT", "DEBUG_0", "DEBUG_1", "DEBUG_2", "DEBUG_3", }; static struct { char *name; u8 num; } advanced_lookup[] = { { "NMI_INTERRUPT_WDG", 0x34 }, { "SYSASSERT", 0x35 }, { "UCODE_VERSION_MISMATCH", 0x37 }, { "BAD_COMMAND", 0x38 }, { "NMI_INTERRUPT_DATA_ACTION_PT", 0x3C }, { "FATAL_ERROR", 0x3D }, { "NMI_TRM_HW_ERR", 0x46 }, { "NMI_INTERRUPT_TRM", 0x4C }, { "NMI_INTERRUPT_BREAK_POINT", 0x54 }, { "NMI_INTERRUPT_WDG_RXF_FULL", 0x5C }, { "NMI_INTERRUPT_WDG_NO_RBD_RXF_FULL", 0x64 }, { "NMI_INTERRUPT_HOST", 0x66 }, { "NMI_INTERRUPT_ACTION_PT", 0x7C }, { "NMI_INTERRUPT_UNKNOWN", 0x84 }, { "NMI_INTERRUPT_INST_ACTION_PT", 0x86 }, { "ADVANCED_SYSASSERT", 0 }, }; static const char *desc_lookup(u32 num) { int i; int max = ARRAY_SIZE(desc_lookup_text); if (num < max) return desc_lookup_text[num]; max = ARRAY_SIZE(advanced_lookup) - 1; for (i = 0; i < max; i++) { if (advanced_lookup[i].num == num) break; } return advanced_lookup[i].name; } #define ERROR_START_OFFSET (1 * sizeof(u32)) #define ERROR_ELEM_SIZE (7 * sizeof(u32)) static void iwl_dump_nic_error_log(struct iwl_trans *trans) { u32 base; struct iwl_error_event_table table; struct iwl_priv *priv = priv(trans); struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); base = trans->shrd->device_pointers.error_event_table; if (trans->shrd->ucode_type == IWL_UCODE_INIT) { if (!base) base = priv->init_errlog_ptr; } else { if (!base) base = priv->inst_errlog_ptr; } if (!iwlagn_hw_valid_rtc_data_addr(base)) { IWL_ERR(trans, "Not valid error log pointer 0x%08X for %s uCode\n", base, (trans->shrd->ucode_type == IWL_UCODE_INIT) ? "Init" : "RT"); return; } iwl_read_targ_mem_words(bus(priv), base, &table, sizeof(table)); if (ERROR_START_OFFSET <= table.valid * ERROR_ELEM_SIZE) { IWL_ERR(trans, "Start IWL Error Log Dump:\n"); IWL_ERR(trans, "Status: 0x%08lX, count: %d\n", trans->shrd->status, table.valid); } trans_pcie->isr_stats.err_code = table.error_id; trace_iwlwifi_dev_ucode_error(priv, table.error_id, table.tsf_low, table.data1, table.data2, table.line, table.blink1, table.blink2, table.ilink1, table.ilink2, table.bcon_time, table.gp1, table.gp2, table.gp3, table.ucode_ver, table.hw_ver, table.brd_ver); IWL_ERR(trans, "0x%08X | %-28s\n", table.error_id, desc_lookup(table.error_id)); IWL_ERR(trans, "0x%08X | uPc\n", table.pc); IWL_ERR(trans, "0x%08X | branchlink1\n", table.blink1); IWL_ERR(trans, "0x%08X | branchlink2\n", table.blink2); IWL_ERR(trans, "0x%08X | interruptlink1\n", table.ilink1); IWL_ERR(trans, "0x%08X | interruptlink2\n", table.ilink2); IWL_ERR(trans, "0x%08X | data1\n", table.data1); IWL_ERR(trans, "0x%08X | data2\n", table.data2); IWL_ERR(trans, "0x%08X | line\n", table.line); IWL_ERR(trans, "0x%08X | beacon time\n", table.bcon_time); IWL_ERR(trans, "0x%08X | tsf low\n", table.tsf_low); IWL_ERR(trans, "0x%08X | tsf hi\n", table.tsf_hi); IWL_ERR(trans, "0x%08X | time gp1\n", table.gp1); IWL_ERR(trans, "0x%08X | time gp2\n", table.gp2); IWL_ERR(trans, "0x%08X | time gp3\n", table.gp3); IWL_ERR(trans, "0x%08X | uCode version\n", table.ucode_ver); IWL_ERR(trans, "0x%08X | hw version\n", table.hw_ver); IWL_ERR(trans, "0x%08X | board version\n", table.brd_ver); IWL_ERR(trans, "0x%08X | hcmd\n", table.hcmd); IWL_ERR(trans, "0x%08X | isr0\n", table.isr0); IWL_ERR(trans, "0x%08X | isr1\n", table.isr1); IWL_ERR(trans, "0x%08X | isr2\n", table.isr2); IWL_ERR(trans, "0x%08X | isr3\n", table.isr3); IWL_ERR(trans, "0x%08X | isr4\n", table.isr4); IWL_ERR(trans, "0x%08X | isr_pref\n", table.isr_pref); IWL_ERR(trans, "0x%08X | wait_event\n", table.wait_event); IWL_ERR(trans, "0x%08X | l2p_control\n", table.l2p_control); IWL_ERR(trans, "0x%08X | l2p_duration\n", table.l2p_duration); IWL_ERR(trans, "0x%08X | l2p_mhvalid\n", table.l2p_mhvalid); IWL_ERR(trans, "0x%08X | l2p_addr_match\n", table.l2p_addr_match); IWL_ERR(trans, "0x%08X | lmpm_pmg_sel\n", table.lmpm_pmg_sel); IWL_ERR(trans, "0x%08X | timestamp\n", table.u_timestamp); IWL_ERR(trans, "0x%08X | flow_handler\n", table.flow_handler); } /** * iwl_irq_handle_error - called for HW or SW error interrupt from card */ static void iwl_irq_handle_error(struct iwl_trans *trans) { struct iwl_priv *priv = priv(trans); /* W/A for WiFi/WiMAX coex and WiMAX own the RF */ if (cfg(priv)->internal_wimax_coex && (!(iwl_read_prph(bus(trans), APMG_CLK_CTRL_REG) & APMS_CLK_VAL_MRB_FUNC_MODE) || (iwl_read_prph(bus(trans), APMG_PS_CTRL_REG) & APMG_PS_CTRL_VAL_RESET_REQ))) { /* * Keep the restart process from trying to send host * commands by clearing the ready bit. */ clear_bit(STATUS_READY, &trans->shrd->status); clear_bit(STATUS_HCMD_ACTIVE, &trans->shrd->status); wake_up(&priv->shrd->wait_command_queue); IWL_ERR(trans, "RF is used by WiMAX\n"); return; } IWL_ERR(trans, "Loaded firmware version: %s\n", priv->hw->wiphy->fw_version); iwl_dump_nic_error_log(trans); iwl_dump_csr(trans); iwl_dump_fh(trans, NULL, false); iwl_dump_nic_event_log(trans, false, NULL, false); #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(trans->shrd) & IWL_DL_FW_ERRORS) iwl_print_rx_config_cmd(priv(trans), IWL_RXON_CTX_BSS); #endif iwlagn_fw_error(priv, false); } #define EVENT_START_OFFSET (4 * sizeof(u32)) /** * iwl_print_event_log - Dump error event log to syslog * */ static int iwl_print_event_log(struct iwl_trans *trans, u32 start_idx, u32 num_events, u32 mode, int pos, char **buf, size_t bufsz) { u32 i; u32 base; /* SRAM byte address of event log header */ u32 event_size; /* 2 u32s, or 3 u32s if timestamp recorded */ u32 ptr; /* SRAM byte address of log data */ u32 ev, time, data; /* event log data */ unsigned long reg_flags; struct iwl_priv *priv = priv(trans); if (num_events == 0) return pos; base = trans->shrd->device_pointers.log_event_table; if (trans->shrd->ucode_type == IWL_UCODE_INIT) { if (!base) base = priv->init_evtlog_ptr; } else { if (!base) base = priv->inst_evtlog_ptr; } if (mode == 0) event_size = 2 * sizeof(u32); else event_size = 3 * sizeof(u32); ptr = base + EVENT_START_OFFSET + (start_idx * event_size); /* Make sure device is powered up for SRAM reads */ spin_lock_irqsave(&bus(trans)->reg_lock, reg_flags); iwl_grab_nic_access(bus(trans)); /* Set starting address; reads will auto-increment */ iwl_write32(bus(trans), HBUS_TARG_MEM_RADDR, ptr); rmb(); /* "time" is actually "data" for mode 0 (no timestamp). * place event id # at far right for easier visual parsing. */ for (i = 0; i < num_events; i++) { ev = iwl_read32(bus(trans), HBUS_TARG_MEM_RDAT); time = iwl_read32(bus(trans), HBUS_TARG_MEM_RDAT); if (mode == 0) { /* data, ev */ if (bufsz) { pos += scnprintf(*buf + pos, bufsz - pos, "EVT_LOG:0x%08x:%04u\n", time, ev); } else { trace_iwlwifi_dev_ucode_event(priv, 0, time, ev); IWL_ERR(trans, "EVT_LOG:0x%08x:%04u\n", time, ev); } } else { data = iwl_read32(bus(trans), HBUS_TARG_MEM_RDAT); if (bufsz) { pos += scnprintf(*buf + pos, bufsz - pos, "EVT_LOGT:%010u:0x%08x:%04u\n", time, data, ev); } else { IWL_ERR(trans, "EVT_LOGT:%010u:0x%08x:%04u\n", time, data, ev); trace_iwlwifi_dev_ucode_event(priv, time, data, ev); } } } /* Allow device to power down */ iwl_release_nic_access(bus(trans)); spin_unlock_irqrestore(&bus(trans)->reg_lock, reg_flags); return pos; } /** * iwl_print_last_event_logs - Dump the newest # of event log to syslog */ static int iwl_print_last_event_logs(struct iwl_trans *trans, u32 capacity, u32 num_wraps, u32 next_entry, u32 size, u32 mode, int pos, char **buf, size_t bufsz) { /* * display the newest DEFAULT_LOG_ENTRIES entries * i.e the entries just before the next ont that uCode would fill. */ if (num_wraps) { if (next_entry < size) { pos = iwl_print_event_log(trans, capacity - (size - next_entry), size - next_entry, mode, pos, buf, bufsz); pos = iwl_print_event_log(trans, 0, next_entry, mode, pos, buf, bufsz); } else pos = iwl_print_event_log(trans, next_entry - size, size, mode, pos, buf, bufsz); } else { if (next_entry < size) { pos = iwl_print_event_log(trans, 0, next_entry, mode, pos, buf, bufsz); } else { pos = iwl_print_event_log(trans, next_entry - size, size, mode, pos, buf, bufsz); } } return pos; } #define DEFAULT_DUMP_EVENT_LOG_ENTRIES (20) int iwl_dump_nic_event_log(struct iwl_trans *trans, bool full_log, char **buf, bool display) { u32 base; /* SRAM byte address of event log header */ u32 capacity; /* event log capacity in # entries */ u32 mode; /* 0 - no timestamp, 1 - timestamp recorded */ u32 num_wraps; /* # times uCode wrapped to top of log */ u32 next_entry; /* index of next entry to be written by uCode */ u32 size; /* # entries that we'll print */ u32 logsize; int pos = 0; size_t bufsz = 0; struct iwl_priv *priv = priv(trans); base = trans->shrd->device_pointers.log_event_table; if (trans->shrd->ucode_type == IWL_UCODE_INIT) { logsize = priv->init_evtlog_size; if (!base) base = priv->init_evtlog_ptr; } else { logsize = priv->inst_evtlog_size; if (!base) base = priv->inst_evtlog_ptr; } if (!iwlagn_hw_valid_rtc_data_addr(base)) { IWL_ERR(trans, "Invalid event log pointer 0x%08X for %s uCode\n", base, (trans->shrd->ucode_type == IWL_UCODE_INIT) ? "Init" : "RT"); return -EINVAL; } /* event log header */ capacity = iwl_read_targ_mem(bus(trans), base); mode = iwl_read_targ_mem(bus(trans), base + (1 * sizeof(u32))); num_wraps = iwl_read_targ_mem(bus(trans), base + (2 * sizeof(u32))); next_entry = iwl_read_targ_mem(bus(trans), base + (3 * sizeof(u32))); if (capacity > logsize) { IWL_ERR(trans, "Log capacity %d is bogus, limit to %d " "entries\n", capacity, logsize); capacity = logsize; } if (next_entry > logsize) { IWL_ERR(trans, "Log write index %d is bogus, limit to %d\n", next_entry, logsize); next_entry = logsize; } size = num_wraps ? capacity : next_entry; /* bail out if nothing in log */ if (size == 0) { IWL_ERR(trans, "Start IWL Event Log Dump: nothing in log\n"); return pos; } #ifdef CONFIG_IWLWIFI_DEBUG if (!(iwl_get_debug_level(trans->shrd) & IWL_DL_FW_ERRORS) && !full_log) size = (size > DEFAULT_DUMP_EVENT_LOG_ENTRIES) ? DEFAULT_DUMP_EVENT_LOG_ENTRIES : size; #else size = (size > DEFAULT_DUMP_EVENT_LOG_ENTRIES) ? DEFAULT_DUMP_EVENT_LOG_ENTRIES : size; #endif IWL_ERR(trans, "Start IWL Event Log Dump: display last %u entries\n", size); #ifdef CONFIG_IWLWIFI_DEBUG if (display) { if (full_log) bufsz = capacity * 48; else bufsz = size * 48; *buf = kmalloc(bufsz, GFP_KERNEL); if (!*buf) return -ENOMEM; } if ((iwl_get_debug_level(trans->shrd) & IWL_DL_FW_ERRORS) || full_log) { /* * if uCode has wrapped back to top of log, * start at the oldest entry, * i.e the next one that uCode would fill. */ if (num_wraps) pos = iwl_print_event_log(trans, next_entry, capacity - next_entry, mode, pos, buf, bufsz); /* (then/else) start at top of log */ pos = iwl_print_event_log(trans, 0, next_entry, mode, pos, buf, bufsz); } else pos = iwl_print_last_event_logs(trans, capacity, num_wraps, next_entry, size, mode, pos, buf, bufsz); #else pos = iwl_print_last_event_logs(trans, capacity, num_wraps, next_entry, size, mode, pos, buf, bufsz); #endif return pos; } /* tasklet for iwlagn interrupt */ void iwl_irq_tasklet(struct iwl_trans *trans) { u32 inta = 0; u32 handled = 0; unsigned long flags; u32 i; #ifdef CONFIG_IWLWIFI_DEBUG u32 inta_mask; #endif struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct isr_statistics *isr_stats = &trans_pcie->isr_stats; spin_lock_irqsave(&trans->shrd->lock, flags); /* Ack/clear/reset pending uCode interrupts. * Note: Some bits in CSR_INT are "OR" of bits in CSR_FH_INT_STATUS, */ /* There is a hardware bug in the interrupt mask function that some * interrupts (i.e. CSR_INT_BIT_SCD) can still be generated even if * they are disabled in the CSR_INT_MASK register. Furthermore the * ICT interrupt handling mechanism has another bug that might cause * these unmasked interrupts fail to be detected. We workaround the * hardware bugs here by ACKing all the possible interrupts so that * interrupt coalescing can still be achieved. */ iwl_write32(bus(trans), CSR_INT, trans_pcie->inta | ~trans_pcie->inta_mask); inta = trans_pcie->inta; #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(trans->shrd) & IWL_DL_ISR) { /* just for debug */ inta_mask = iwl_read32(bus(trans), CSR_INT_MASK); IWL_DEBUG_ISR(trans, "inta 0x%08x, enabled 0x%08x\n ", inta, inta_mask); } #endif spin_unlock_irqrestore(&trans->shrd->lock, flags); /* saved interrupt in inta variable now we can reset trans_pcie->inta */ trans_pcie->inta = 0; /* Now service all interrupt bits discovered above. */ if (inta & CSR_INT_BIT_HW_ERR) { IWL_ERR(trans, "Hardware error detected. Restarting.\n"); /* Tell the device to stop sending interrupts */ iwl_disable_interrupts(trans); isr_stats->hw++; iwl_irq_handle_error(trans); handled |= CSR_INT_BIT_HW_ERR; return; } #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(trans->shrd) & (IWL_DL_ISR)) { /* NIC fires this, but we don't use it, redundant with WAKEUP */ if (inta & CSR_INT_BIT_SCD) { IWL_DEBUG_ISR(trans, "Scheduler finished to transmit " "the frame/frames.\n"); isr_stats->sch++; } /* Alive notification via Rx interrupt will do the real work */ if (inta & CSR_INT_BIT_ALIVE) { IWL_DEBUG_ISR(trans, "Alive interrupt\n"); isr_stats->alive++; } } #endif /* Safely ignore these bits for debug checks below */ inta &= ~(CSR_INT_BIT_SCD | CSR_INT_BIT_ALIVE); /* HW RF KILL switch toggled */ if (inta & CSR_INT_BIT_RF_KILL) { int hw_rf_kill = 0; if (!(iwl_read32(bus(trans), CSR_GP_CNTRL) & CSR_GP_CNTRL_REG_FLAG_HW_RF_KILL_SW)) hw_rf_kill = 1; IWL_WARN(trans, "RF_KILL bit toggled to %s.\n", hw_rf_kill ? "disable radio" : "enable radio"); isr_stats->rfkill++; /* driver only loads ucode once setting the interface up. * the driver allows loading the ucode even if the radio * is killed. Hence update the killswitch state here. The * rfkill handler will care about restarting if needed. */ if (!test_bit(STATUS_ALIVE, &trans->shrd->status)) { if (hw_rf_kill) set_bit(STATUS_RF_KILL_HW, &trans->shrd->status); else clear_bit(STATUS_RF_KILL_HW, &trans->shrd->status); iwl_set_hw_rfkill_state(priv(trans), hw_rf_kill); } handled |= CSR_INT_BIT_RF_KILL; } /* Chip got too hot and stopped itself */ if (inta & CSR_INT_BIT_CT_KILL) { IWL_ERR(trans, "Microcode CT kill error detected.\n"); isr_stats->ctkill++; handled |= CSR_INT_BIT_CT_KILL; } /* Error detected by uCode */ if (inta & CSR_INT_BIT_SW_ERR) { IWL_ERR(trans, "Microcode SW error detected. " " Restarting 0x%X.\n", inta); isr_stats->sw++; iwl_irq_handle_error(trans); handled |= CSR_INT_BIT_SW_ERR; } /* uCode wakes up after power-down sleep */ if (inta & CSR_INT_BIT_WAKEUP) { IWL_DEBUG_ISR(trans, "Wakeup interrupt\n"); iwl_rx_queue_update_write_ptr(trans, &trans_pcie->rxq); for (i = 0; i < hw_params(trans).max_txq_num; i++) iwl_txq_update_write_ptr(trans, &trans_pcie->txq[i]); isr_stats->wakeup++; handled |= CSR_INT_BIT_WAKEUP; } /* All uCode command responses, including Tx command responses, * Rx "responses" (frame-received notification), and other * notifications from uCode come through here*/ if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX | CSR_INT_BIT_RX_PERIODIC)) { IWL_DEBUG_ISR(trans, "Rx interrupt\n"); if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) { handled |= (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX); iwl_write32(bus(trans), CSR_FH_INT_STATUS, CSR_FH_INT_RX_MASK); } if (inta & CSR_INT_BIT_RX_PERIODIC) { handled |= CSR_INT_BIT_RX_PERIODIC; iwl_write32(bus(trans), CSR_INT, CSR_INT_BIT_RX_PERIODIC); } /* Sending RX interrupt require many steps to be done in the * the device: * 1- write interrupt to current index in ICT table. * 2- dma RX frame. * 3- update RX shared data to indicate last write index. * 4- send interrupt. * This could lead to RX race, driver could receive RX interrupt * but the shared data changes does not reflect this; * periodic interrupt will detect any dangling Rx activity. */ /* Disable periodic interrupt; we use it as just a one-shot. */ iwl_write8(bus(trans), CSR_INT_PERIODIC_REG, CSR_INT_PERIODIC_DIS); iwl_rx_handle(trans); /* * Enable periodic interrupt in 8 msec only if we received * real RX interrupt (instead of just periodic int), to catch * any dangling Rx interrupt. If it was just the periodic * interrupt, there was no dangling Rx activity, and no need * to extend the periodic interrupt; one-shot is enough. */ if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) iwl_write8(bus(trans), CSR_INT_PERIODIC_REG, CSR_INT_PERIODIC_ENA); isr_stats->rx++; } /* This "Tx" DMA channel is used only for loading uCode */ if (inta & CSR_INT_BIT_FH_TX) { iwl_write32(bus(trans), CSR_FH_INT_STATUS, CSR_FH_INT_TX_MASK); IWL_DEBUG_ISR(trans, "uCode load interrupt\n"); isr_stats->tx++; handled |= CSR_INT_BIT_FH_TX; /* Wake up uCode load routine, now that load is complete */ trans->ucode_write_complete = 1; wake_up(&trans->shrd->wait_command_queue); } if (inta & ~handled) { IWL_ERR(trans, "Unhandled INTA bits 0x%08x\n", inta & ~handled); isr_stats->unhandled++; } if (inta & ~(trans_pcie->inta_mask)) { IWL_WARN(trans, "Disabled INTA bits 0x%08x were pending\n", inta & ~trans_pcie->inta_mask); } /* Re-enable all interrupts */ /* only Re-enable if disabled by irq */ if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status)) iwl_enable_interrupts(trans); /* Re-enable RF_KILL if it occurred */ else if (handled & CSR_INT_BIT_RF_KILL) iwl_enable_rfkill_int(priv(trans)); } /****************************************************************************** * * ICT functions * ******************************************************************************/ /* a device (PCI-E) page is 4096 bytes long */ #define ICT_SHIFT 12 #define ICT_SIZE (1 << ICT_SHIFT) #define ICT_COUNT (ICT_SIZE / sizeof(u32)) /* Free dram table */ void iwl_free_isr_ict(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); if (trans_pcie->ict_tbl) { dma_free_coherent(bus(trans)->dev, ICT_SIZE, trans_pcie->ict_tbl, trans_pcie->ict_tbl_dma); trans_pcie->ict_tbl = NULL; trans_pcie->ict_tbl_dma = 0; } } /* * allocate dram shared table, it is an aligned memory * block of ICT_SIZE. * also reset all data related to ICT table interrupt. */ int iwl_alloc_isr_ict(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); trans_pcie->ict_tbl = dma_alloc_coherent(bus(trans)->dev, ICT_SIZE, &trans_pcie->ict_tbl_dma, GFP_KERNEL); if (!trans_pcie->ict_tbl) return -ENOMEM; /* just an API sanity check ... it is guaranteed to be aligned */ if (WARN_ON(trans_pcie->ict_tbl_dma & (ICT_SIZE - 1))) { iwl_free_isr_ict(trans); return -EINVAL; } IWL_DEBUG_ISR(trans, "ict dma addr %Lx\n", (unsigned long long)trans_pcie->ict_tbl_dma); IWL_DEBUG_ISR(trans, "ict vir addr %p\n", trans_pcie->ict_tbl); /* reset table and index to all 0 */ memset(trans_pcie->ict_tbl, 0, ICT_SIZE); trans_pcie->ict_index = 0; /* add periodic RX interrupt */ trans_pcie->inta_mask |= CSR_INT_BIT_RX_PERIODIC; return 0; } /* Device is going up inform it about using ICT interrupt table, * also we need to tell the driver to start using ICT interrupt. */ int iwl_reset_ict(struct iwl_trans *trans) { u32 val; unsigned long flags; struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); if (!trans_pcie->ict_tbl) return 0; spin_lock_irqsave(&trans->shrd->lock, flags); iwl_disable_interrupts(trans); memset(trans_pcie->ict_tbl, 0, ICT_SIZE); val = trans_pcie->ict_tbl_dma >> ICT_SHIFT; val |= CSR_DRAM_INT_TBL_ENABLE; val |= CSR_DRAM_INIT_TBL_WRAP_CHECK; IWL_DEBUG_ISR(trans, "CSR_DRAM_INT_TBL_REG =0x%x\n", val); iwl_write32(bus(trans), CSR_DRAM_INT_TBL_REG, val); trans_pcie->use_ict = true; trans_pcie->ict_index = 0; iwl_write32(bus(trans), CSR_INT, trans_pcie->inta_mask); iwl_enable_interrupts(trans); spin_unlock_irqrestore(&trans->shrd->lock, flags); return 0; } /* Device is going down disable ict interrupt usage */ void iwl_disable_ict(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); unsigned long flags; spin_lock_irqsave(&trans->shrd->lock, flags); trans_pcie->use_ict = false; spin_unlock_irqrestore(&trans->shrd->lock, flags); } static irqreturn_t iwl_isr(int irq, void *data) { struct iwl_trans *trans = data; struct iwl_trans_pcie *trans_pcie; u32 inta, inta_mask; unsigned long flags; #ifdef CONFIG_IWLWIFI_DEBUG u32 inta_fh; #endif if (!trans) return IRQ_NONE; trace_iwlwifi_dev_irq(priv(trans)); trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); spin_lock_irqsave(&trans->shrd->lock, flags); /* Disable (but don't clear!) interrupts here to avoid * back-to-back ISRs and sporadic interrupts from our NIC. * If we have something to service, the tasklet will re-enable ints. * If we *don't* have something, we'll re-enable before leaving here. */ inta_mask = iwl_read32(bus(trans), CSR_INT_MASK); /* just for debug */ iwl_write32(bus(trans), CSR_INT_MASK, 0x00000000); /* Discover which interrupts are active/pending */ inta = iwl_read32(bus(trans), CSR_INT); /* Ignore interrupt if there's nothing in NIC to service. * This may be due to IRQ shared with another device, * or due to sporadic interrupts thrown from our NIC. */ if (!inta) { IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n"); goto none; } if ((inta == 0xFFFFFFFF) || ((inta & 0xFFFFFFF0) == 0xa5a5a5a0)) { /* Hardware disappeared. It might have already raised * an interrupt */ IWL_WARN(trans, "HARDWARE GONE?? INTA == 0x%08x\n", inta); goto unplugged; } #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(trans->shrd) & (IWL_DL_ISR)) { inta_fh = iwl_read32(bus(trans), CSR_FH_INT_STATUS); IWL_DEBUG_ISR(trans, "ISR inta 0x%08x, enabled 0x%08x, " "fh 0x%08x\n", inta, inta_mask, inta_fh); } #endif trans_pcie->inta |= inta; /* iwl_irq_tasklet() will service interrupts and re-enable them */ if (likely(inta)) tasklet_schedule(&trans_pcie->irq_tasklet); else if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) && !trans_pcie->inta) iwl_enable_interrupts(trans); unplugged: spin_unlock_irqrestore(&trans->shrd->lock, flags); return IRQ_HANDLED; none: /* re-enable interrupts here since we don't have anything to service. */ /* only Re-enable if disabled by irq and no schedules tasklet. */ if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) && !trans_pcie->inta) iwl_enable_interrupts(trans); spin_unlock_irqrestore(&trans->shrd->lock, flags); return IRQ_NONE; } /* interrupt handler using ict table, with this interrupt driver will * stop using INTA register to get device's interrupt, reading this register * is expensive, device will write interrupts in ICT dram table, increment * index then will fire interrupt to driver, driver will OR all ICT table * entries from current index up to table entry with 0 value. the result is * the interrupt we need to service, driver will set the entries back to 0 and * set index. */ irqreturn_t iwl_isr_ict(int irq, void *data) { struct iwl_trans *trans = data; struct iwl_trans_pcie *trans_pcie; u32 inta, inta_mask; u32 val = 0; u32 read; unsigned long flags; if (!trans) return IRQ_NONE; trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); /* dram interrupt table not set yet, * use legacy interrupt. */ if (!trans_pcie->use_ict) return iwl_isr(irq, data); trace_iwlwifi_dev_irq(priv(trans)); spin_lock_irqsave(&trans->shrd->lock, flags); /* Disable (but don't clear!) interrupts here to avoid * back-to-back ISRs and sporadic interrupts from our NIC. * If we have something to service, the tasklet will re-enable ints. * If we *don't* have something, we'll re-enable before leaving here. */ inta_mask = iwl_read32(bus(trans), CSR_INT_MASK); /* just for debug */ iwl_write32(bus(trans), CSR_INT_MASK, 0x00000000); /* Ignore interrupt if there's nothing in NIC to service. * This may be due to IRQ shared with another device, * or due to sporadic interrupts thrown from our NIC. */ read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]); trace_iwlwifi_dev_ict_read(priv(trans), trans_pcie->ict_index, read); if (!read) { IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n"); goto none; } /* * Collect all entries up to the first 0, starting from ict_index; * note we already read at ict_index. */ do { val |= read; IWL_DEBUG_ISR(trans, "ICT index %d value 0x%08X\n", trans_pcie->ict_index, read); trans_pcie->ict_tbl[trans_pcie->ict_index] = 0; trans_pcie->ict_index = iwl_queue_inc_wrap(trans_pcie->ict_index, ICT_COUNT); read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]); trace_iwlwifi_dev_ict_read(priv(trans), trans_pcie->ict_index, read); } while (read); /* We should not get this value, just ignore it. */ if (val == 0xffffffff) val = 0; /* * this is a w/a for a h/w bug. the h/w bug may cause the Rx bit * (bit 15 before shifting it to 31) to clear when using interrupt * coalescing. fortunately, bits 18 and 19 stay set when this happens * so we use them to decide on the real state of the Rx bit. * In order words, bit 15 is set if bit 18 or bit 19 are set. */ if (val & 0xC0000) val |= 0x8000; inta = (0xff & val) | ((0xff00 & val) << 16); IWL_DEBUG_ISR(trans, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n", inta, inta_mask, val); inta &= trans_pcie->inta_mask; trans_pcie->inta |= inta; /* iwl_irq_tasklet() will service interrupts and re-enable them */ if (likely(inta)) tasklet_schedule(&trans_pcie->irq_tasklet); else if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) && !trans_pcie->inta) { /* Allow interrupt if was disabled by this handler and * no tasklet was schedules, We should not enable interrupt, * tasklet will enable it. */ iwl_enable_interrupts(trans); } spin_unlock_irqrestore(&trans->shrd->lock, flags); return IRQ_HANDLED; none: /* re-enable interrupts here since we don't have anything to service. * only Re-enable if disabled by irq. */ if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) && !trans_pcie->inta) iwl_enable_interrupts(trans); spin_unlock_irqrestore(&trans->shrd->lock, flags); return IRQ_NONE; }