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-mem.c b/drivers/usb/host/xhci-mem.c
index 77689bd..487bc08 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1772,6 +1772,7 @@
{
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
struct dev_info *dev_info, *next;
+ struct xhci_cd *cur_cd, *next_cd;
unsigned long flags;
int size;
int i, j, num_ports;
@@ -1795,6 +1796,11 @@
xhci_ring_free(xhci, xhci->cmd_ring);
xhci->cmd_ring = NULL;
xhci_dbg(xhci, "Freed command ring\n");
+ list_for_each_entry_safe(cur_cd, next_cd,
+ &xhci->cancel_cmd_list, cancel_cmd_list) {
+ list_del(&cur_cd->cancel_cmd_list);
+ kfree(cur_cd);
+ }
for (i = 1; i < MAX_HC_SLOTS; ++i)
xhci_free_virt_device(xhci, i);
@@ -2340,6 +2346,7 @@
xhci->cmd_ring = xhci_ring_alloc(xhci, 1, 1, TYPE_COMMAND, flags);
if (!xhci->cmd_ring)
goto fail;
+ INIT_LIST_HEAD(&xhci->cancel_cmd_list);
xhci_dbg(xhci, "Allocated command ring at %p\n", xhci->cmd_ring);
xhci_dbg(xhci, "First segment DMA is 0x%llx\n",
(unsigned long long)xhci->cmd_ring->first_seg->dma);