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xHCI: add aborting command ring function

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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 7ed603ecf8 "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
This commit is contained in:
Elric Fu
2012-06-27 16:31:12 +08:00
committed by Sarah Sharp
parent c181bc5b5d
commit b92cc66c04
4 changed files with 128 additions and 1 deletions
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7
drivers/usb/host/xhci-mem.c
View File

@@ -1772,6 +1772,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
{
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 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
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 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
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);