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authorLu Baolu <baolu.lu@linux.intel.com>2015-11-18 11:48:21 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-11-18 20:24:41 +0300
commit42df7215facf27be8d53e657dd4a12d4ebad0a44 (patch)
treeef2c80195877d04cd4438fadea2201c3b6d4b2ec /drivers/usb
parenta5964396190d0c40dd549c23848c282fffa5d1f2 (diff)
downloadlinux-42df7215facf27be8d53e657dd4a12d4ebad0a44.tar.xz
usb: xhci: fix checking ep busy for CFC
Function ep_ring_is_processing() checks the dequeue pointer in endpoint context to know whether an endpoint is busy with processing TRBs. This is not correct since dequeue pointer field in an endpoint context is only valid when the endpoint is in Halted or Stopped states. This buggy code causes audio noise when playing sound with USB headset connected to host controllers which support CFC (one of xhci 1.1 features). This patch should exist in stable kernel since v4.3. Reported-and-tested-by: YD Tseng <yd_tseng@asmedia.com.tw> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Cc: stable <stable@vger.kernel.org> # v4.3 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/xhci-ring.c32
1 files changed, 6 insertions, 26 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index fa836251ca21..6c5e8133cf87 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3896,28 +3896,6 @@ cleanup:
return ret;
}
-static int ep_ring_is_processing(struct xhci_hcd *xhci,
- int slot_id, unsigned int ep_index)
-{
- struct xhci_virt_device *xdev;
- struct xhci_ring *ep_ring;
- struct xhci_ep_ctx *ep_ctx;
- struct xhci_virt_ep *xep;
- dma_addr_t hw_deq;
-
- xdev = xhci->devs[slot_id];
- xep = &xhci->devs[slot_id]->eps[ep_index];
- ep_ring = xep->ring;
- ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
-
- if ((le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) != EP_STATE_RUNNING)
- return 0;
-
- hw_deq = le64_to_cpu(ep_ctx->deq) & ~EP_CTX_CYCLE_MASK;
- return (hw_deq !=
- xhci_trb_virt_to_dma(ep_ring->enq_seg, ep_ring->enqueue));
-}
-
/*
* Check transfer ring to guarantee there is enough room for the urb.
* Update ISO URB start_frame and interval.
@@ -3983,10 +3961,12 @@ int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
}
/* Calculate the start frame and put it in urb->start_frame. */
- if (HCC_CFC(xhci->hcc_params) &&
- ep_ring_is_processing(xhci, slot_id, ep_index)) {
- urb->start_frame = xep->next_frame_id;
- goto skip_start_over;
+ if (HCC_CFC(xhci->hcc_params) && !list_empty(&ep_ring->td_list)) {
+ if ((le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) ==
+ EP_STATE_RUNNING) {
+ urb->start_frame = xep->next_frame_id;
+ goto skip_start_over;
+ }
}
start_frame = readl(&xhci->run_regs->microframe_index);