This is a note to let you know that I've just added the patch titled
usb: xhci: fix checking ep busy for CFC
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 42df7215facf27be8d53e657dd4a12d4ebad0a44 Mon Sep 17 00:00:00 2001
From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Date: Wed, 18 Nov 2015 10:48:21 +0200
Subject: 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@xxxxxxxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx> # v4.3
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
--
2.6.2
--
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