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authorMathias Nyman <mathias.nyman@linux.intel.com>2013-08-30 18:25:49 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-05 07:13:10 -0700
commit57ad776884c52610af5e00d53e9755f2a8d50bbd (patch)
tree0655ae72897b7c057e2bfcc01e16dc483160891b
parent4bc8e1356cf9c7c2dbff522671a5d6d33d49c2ba (diff)
downloadlinux-linaro-stable-57ad776884c52610af5e00d53e9755f2a8d50bbd.tar.gz
xhci: Ensure a command structure points to the correct trb on the command ring
commit ec7e43e2d98173483866fe2e4e690143626b659c upstream. If a command on the command ring needs to be cancelled before it is handled it can be turned to a no-op operation when the ring is stopped. We want to store the command ring enqueue pointer in the command structure when the command in enqueued for the cancellation case. Some commands used to store the command ring dequeue pointers instead of enqueue (these often worked because enqueue happends to equal dequeue quite often) Other commands correctly used the enqueue pointer but did not check if it pointed to a valid trb or a link trb, this caused for example stop endpoint command to timeout in xhci_stop_device() in about 2% of suspend/resume cases. This should also solve some weird behavior happening in command cancellation cases. This patch is based on a patch submitted by Sarah Sharp to linux-usb, but then forgotten: http://marc.info/?l=linux-usb&m=136269803207465&w=2 This patch should be backported to kernels as old as 3.7, that contain the commit b92cc66c047ff7cf587b318fe377061a353c120f "xHCI: add aborting command ring function" Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/host/xhci-hub.c2
-rw-r--r--drivers/usb/host/xhci-ring.c10
-rw-r--r--drivers/usb/host/xhci.c25
-rw-r--r--drivers/usb/host/xhci.h1
4 files changed, 17 insertions, 21 deletions
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 187a3ec1069a..7cdcfd024744 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -286,7 +286,7 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue)
xhci_queue_stop_endpoint(xhci, slot_id, i, suspend);
}
- cmd->command_trb = xhci->cmd_ring->enqueue;
+ cmd->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
list_add_tail(&cmd->cmd_list, &virt_dev->cmd_list);
xhci_queue_stop_endpoint(xhci, slot_id, 0, suspend);
xhci_ring_cmd_db(xhci);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index cc3bfc5d590d..8192e32be87c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -122,6 +122,16 @@ static int enqueue_is_link_trb(struct xhci_ring *ring)
return TRB_TYPE_LINK_LE32(link->control);
}
+union xhci_trb *xhci_find_next_enqueue(struct xhci_ring *ring)
+{
+ /* Enqueue pointer can be left pointing to the link TRB,
+ * we must handle that
+ */
+ if (TRB_TYPE_LINK_LE32(ring->enqueue->link.control))
+ return ring->enq_seg->next->trbs;
+ return ring->enqueue;
+}
+
/* Updates trb to point to the next TRB in the ring, and updates seg if the next
* TRB is in a new segment. This does not skip over link TRBs, and it does not
* effect the ring dequeue or enqueue pointers.
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f4a49c45299c..4a5251f3614c 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2592,15 +2592,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
if (command) {
cmd_completion = command->completion;
cmd_status = &command->status;
- command->command_trb = xhci->cmd_ring->enqueue;
-
- /* Enqueue pointer can be left pointing to the link TRB,
- * we must handle that
- */
- if (TRB_TYPE_LINK_LE32(command->command_trb->link.control))
- command->command_trb =
- xhci->cmd_ring->enq_seg->next->trbs;
-
+ command->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
list_add_tail(&command->cmd_list, &virt_dev->cmd_list);
} else {
cmd_completion = &virt_dev->cmd_completion;
@@ -2608,7 +2600,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
}
init_completion(cmd_completion);
- cmd_trb = xhci->cmd_ring->dequeue;
+ cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
if (!ctx_change)
ret = xhci_queue_configure_endpoint(xhci, in_ctx->dma,
udev->slot_id, must_succeed);
@@ -3393,14 +3385,7 @@ int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
/* Attempt to submit the Reset Device command to the command ring */
spin_lock_irqsave(&xhci->lock, flags);
- reset_device_cmd->command_trb = xhci->cmd_ring->enqueue;
-
- /* Enqueue pointer can be left pointing to the link TRB,
- * we must handle that
- */
- if (TRB_TYPE_LINK_LE32(reset_device_cmd->command_trb->link.control))
- reset_device_cmd->command_trb =
- xhci->cmd_ring->enq_seg->next->trbs;
+ reset_device_cmd->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
list_add_tail(&reset_device_cmd->cmd_list, &virt_dev->cmd_list);
ret = xhci_queue_reset_device(xhci, slot_id);
@@ -3604,7 +3589,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
union xhci_trb *cmd_trb;
spin_lock_irqsave(&xhci->lock, flags);
- cmd_trb = xhci->cmd_ring->dequeue;
+ cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
ret = xhci_queue_slot_control(xhci, TRB_ENABLE_SLOT, 0);
if (ret) {
spin_unlock_irqrestore(&xhci->lock, flags);
@@ -3731,7 +3716,7 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
spin_lock_irqsave(&xhci->lock, flags);
- cmd_trb = xhci->cmd_ring->dequeue;
+ cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
udev->slot_id);
if (ret) {
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3638f1d779e6..627fcd9388ca 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1821,6 +1821,7 @@ int xhci_cancel_cmd(struct xhci_hcd *xhci, struct xhci_command *command,
union xhci_trb *cmd_trb);
void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int slot_id,
unsigned int ep_index, unsigned int stream_id);
+union xhci_trb *xhci_find_next_enqueue(struct xhci_ring *ring);
/* xHCI roothub code */
void xhci_set_link_state(struct xhci_hcd *xhci, __le32 __iomem **port_array,