From e62a959afd2b1a13b27dda9d03f10c7feb36aa9b Mon Sep 17 00:00:00 2001 From: Mark Cave-Ayland Date: Wed, 19 May 2021 11:08:01 +0100 Subject: esp: ensure PDMA write transfers are flushed from the FIFO to the target immediately After each PDMA write transfer the MacOS CDROM driver waits until the FIFO is empty (i.e. its contents have been written out to the SCSI bus) by polling the FIFO count register until it reads 0. This doesn't work with the current PDMA write implementation which waits until either the FIFO is full or the transfer is complete before invoking the PDMA callback to process the FIFO contents. Change the PDMA write transfer logic so that the PDMA callback is invoked after each PDMA write to transfer the FIFO contents to the target buffer immediately, and hence avoid getting stuck in the FIFO count register polling loop. Signed-off-by: Mark Cave-Ayland Message-Id: <20210519100803.10293-4-mark.cave-ayland@ilande.co.uk> Signed-off-by: Paolo Bonzini --- hw/scsi/esp.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) (limited to 'hw') diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index a0dab319f2..8e314ef156 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -338,9 +338,9 @@ static void do_cmd(ESPState *s) static void satn_pdma_cb(ESPState *s) { - s->do_cmd = 0; - if (!fifo8_is_empty(&s->cmdfifo)) { + if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) { s->cmdfifo_cdb_offset = 1; + s->do_cmd = 0; do_cmd(s); } } @@ -369,12 +369,9 @@ static void handle_satn(ESPState *s) static void s_without_satn_pdma_cb(ESPState *s) { - uint32_t len; - - s->do_cmd = 0; - len = fifo8_num_used(&s->cmdfifo); - if (len) { + if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) { s->cmdfifo_cdb_offset = 0; + s->do_cmd = 0; do_busid_cmd(s, 0); } } @@ -403,8 +400,7 @@ static void handle_s_without_atn(ESPState *s) static void satn_stop_pdma_cb(ESPState *s) { - s->do_cmd = 0; - if (!fifo8_is_empty(&s->cmdfifo)) { + if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) { trace_esp_handle_satn_stop(fifo8_num_used(&s->cmdfifo)); s->do_cmd = 1; s->cmdfifo_cdb_offset = 1; @@ -493,6 +489,11 @@ static void do_dma_pdma_cb(ESPState *s) uint32_t n; if (s->do_cmd) { + /* Ensure we have received complete command after SATN and stop */ + if (esp_get_tc(s) || fifo8_is_empty(&s->cmdfifo)) { + return; + } + s->ti_size = 0; s->do_cmd = 0; do_cmd(s); @@ -1220,7 +1221,6 @@ static void sysbus_esp_pdma_write(void *opaque, hwaddr addr, { SysBusESPState *sysbus = opaque; ESPState *s = ESP(&sysbus->esp); - uint32_t dmalen; trace_esp_pdma_write(size); @@ -1233,10 +1233,7 @@ static void sysbus_esp_pdma_write(void *opaque, hwaddr addr, esp_pdma_write(s, val); break; } - dmalen = esp_get_tc(s); - if (dmalen == 0 || fifo8_num_free(&s->fifo) < 2) { - s->pdma_cb(s); - } + s->pdma_cb(s); } static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr, -- cgit v1.2.3