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authorLu Baolu <baolu.lu@linux.intel.com>2015-11-18 10:48:21 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-09 14:34:41 -0500
commit72655363eb6e000aef420780655f11f1a4c1c2d9 (patch)
treea7cc1bba846a59e450a9a5e81d24ba1b29e1dbe3
parentc88860cd6ec20ca7d518273f1bf01f1c0f3b2d80 (diff)
usb: xhci: fix checking ep busy for CFC
commit 42df7215facf27be8d53e657dd4a12d4ebad0a44 upstream. 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> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 97ffe3997273..fe9e2d3a223c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3914,28 +3914,6 @@ 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.
@@ -4001,10 +3979,12 @@ 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);