xHCI: add aborting command ring function
Software have to abort command ring and cancel command
when a command is failed or hang. Otherwise, the command
ring will hang up and can't handle the others. An example
of a command that may hang is the Address Device Command,
because waiting for a SET_ADDRESS request to be acknowledged
by a USB device is outside of the xHC's ability to control.
To cancel a command, software will initialize a command
descriptor for the cancel command, and add it into a
cancel_cmd_list of xhci.
Sarah: Fixed missing newline on "Have the command ring been stopped?"
debugging statement.
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>
Cc: stable@vger.kernel.org
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f425356e..3f0763d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -51,7 +51,7 @@
* handshake done). There are two failure modes: "usec" have passed (major
* hardware flakeout), or the register reads as all-ones (hardware removed).
*/
-static int handshake(struct xhci_hcd *xhci, void __iomem *ptr,
+int handshake(struct xhci_hcd *xhci, void __iomem *ptr,
u32 mask, u32 done, int usec)
{
u32 result;