From 42df7215facf27be8d53e657dd4a12d4ebad0a44 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Wed, 18 Nov 2015 10:48:21 +0200 Subject: [PATCH] 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 Signed-off-by: Lu Baolu Cc: stable # v4.3 Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 32 ++++++-------------------------- 1 file 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); -- 2.20.1