[ 025/147] xHCI: cancel command after command timeout

Ben Hutchings
2012-10-14T14:45:54Z

From: Elric Fu <elricfu1@gmail.com>

commit 6e4468b9a0793dfb53eb80d9fe52c739b13b27fd upstream.

The patch is used to cancel command when the command isn't
acknowledged and a timeout occurs.

This patch should be backported to kernels as old as 3.0, that contain
the commit 7ed603ecf8b68ab81f4c83097d3063d43ec73bb8 "xhci: Add an
assertion to check for virt_dev=0 bug." That commit papers over a NULL
pointer dereference, and this patch fixes the underlying issue that
caused the NULL pointer dereference.

Signed-off-by: Elric Fu <elricfu1@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Miroslav Sabljic <miroslav.sabljic@avl.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/host/xhci.c | 26 +++++++++++++++++++-------
drivers/usb/host/xhci.h | 3 +++
2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3f0763d..b95e3e8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2402,6 +2402,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
struct completion *cmd_completion;
u32 *cmd_status;
struct xhci_virt_device *virt_dev;
+ union xhci_trb *cmd_trb;

spin_lock_irqsave(&xhci->lock, flags);
virt_dev = xhci->devs[udev->slot_id];
@@ -2447,6 +2448,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
}
init_completion(cmd_completion);

+ cmd_trb = xhci->cmd_ring->dequeue;
if (!ctx_change)
ret = xhci_queue_configure_endpoint(xhci, in_ctx->dma,
udev->slot_id, must_succeed);
@@ -2468,14 +2470,17 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
/* Wait for the configure endpoint command to complete */
timeleft = wait_for_completion_interruptible_timeout(
cmd_completion,
- USB_CTRL_SET_TIMEOUT);
+ XHCI_CMD_DEFAULT_TIMEOUT);
if (timeleft <= 0) {
xhci_warn(xhci, "%s while waiting for %s command\n",
timeleft == 0 ? "Timeout" : "Signal",
ctx_change == 0 ?
"configure endpoint" :
"evaluate context");
- /* FIXME cancel the configure endpoint command */
+ /* cancel the configure endpoint command */
+ ret = xhci_cancel_cmd(xhci, command, cmd_trb);
+ if (ret < 0)
+ return ret;
return -ETIME;
}

@@ -3424,8 +3429,10 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
unsigned long flags;
int timeleft;
int ret;
+ union xhci_trb *cmd_trb;

spin_lock_irqsave(&xhci->lock, flags);
+ cmd_trb = xhci->cmd_ring->dequeue;
ret = xhci_queue_slot_control(xhci, TRB_ENABLE_SLOT, 0);
if (ret) {
spin_unlock_irqrestore(&xhci->lock, flags);
@@ -3437,12 +3444,12 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)

/* XXX: how much time for xHC slot assignment? */
timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
- USB_CTRL_SET_TIMEOUT);
+ XHCI_CMD_DEFAULT_TIMEOUT);
if (timeleft <= 0) {
xhci_warn(xhci, "%s while waiting for a slot\n",
timeleft == 0 ? "Timeout" : "Signal");
- /* FIXME cancel the enable slot request */
- return 0;
+ /* cancel the enable slot request */
+ return xhci_cancel_cmd(xhci, NULL, cmd_trb);
}

if (!xhci->slot_id) {
@@ -3503,6 +3510,7 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
struct xhci_slot_ctx *slot_ctx;
struct xhci_input_control_ctx *ctrl_ctx;
u64 temp_64;
+ union xhci_trb *cmd_trb;

if (!udev->slot_id) {
xhci_dbg(xhci, "Bad Slot ID %d\n", udev->slot_id);
@@ -3541,6 +3549,7 @@ 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;
ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
udev->slot_id);
if (ret) {
@@ -3553,7 +3562,7 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)

/* ctrl tx can take up to 5 sec; XXX: need more time for xHC? */
timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
- USB_CTRL_SET_TIMEOUT);
+ XHCI_CMD_DEFAULT_TIMEOUT);
/* FIXME: From section 4.3.4: "Software shall be responsible for timing
* the SetAddress() "recovery interval" required by USB and aborting the
* command on a timeout.
@@ -3561,7 +3570,10 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
if (timeleft <= 0) {
xhci_warn(xhci, "%s while waiting for address device command\n",
timeleft == 0 ? "Timeout" : "Signal");
- /* FIXME cancel the address device command */
+ /* cancel the address device command */
+ ret = xhci_cancel_cmd(xhci, NULL, cmd_trb);
+ if (ret < 0)
+ return ret;
return -ETIME;
}

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index fdfcebf..e81ccfa 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1256,6 +1256,9 @@ struct xhci_td {
union xhci_trb *last_trb;
};

+/* xHCI command default timeout value */
+#define XHCI_CMD_DEFAULT_TIMEOUT (5 * HZ)
+
/* command descriptor */
struct xhci_cd {
struct list_head cancel_cmd_list;