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UPSTREAM: usb: gadget: u_audio: update hw_ptr in iso_complete after data copied

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In u_audio_iso_complete, the runtime hw_ptr is updated before the
data is actually copied over to/from the buffer/dma area. When
ALSA uses this hw_ptr, the data may not actually be available to
be used. This causes trash/stale audio to play/record. This
patch updates the hw_ptr after the data has been copied to avoid
this.

Change-Id: I22e4479e2978740708be92ce27d8cb61789a7062
Fixes: 132fcb4608 ("usb: gadget: Add Audio Class 2.0 Driver")
Signed-off-by: Joshua Frkuska <joshua_frkuska@mentor.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: William Wu <william.wu@rock-chips.com>
(cherry picked from commit 6b37bd78d3)
This commit is contained in:
Joshua Frkuska
2018-06-21 17:22:48 +02:00
committed by Tao Huang
parent f81ce6a555
commit 6ec0a4d7f6
1 changed files with 5 additions and 1 deletions
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6
drivers/usb/gadget/function/u_audio.c
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@@ -152,7 +152,6 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
update_alsa = true;
hw_ptr = prm->hw_ptr;
prm->hw_ptr = (prm->hw_ptr + req->actual) % prm->dma_bytes;
spin_unlock_irqrestore(&prm->lock, flags);
@@ -177,6 +176,11 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
}
}
spin_lock_irqsave(&prm->lock, flags);
/* update hw_ptr after data is copied to memory */
prm->hw_ptr = (hw_ptr + req->actual) % prm->dma_bytes;
spin_unlock_irqrestore(&prm->lock, flags);
exit:
if (usb_ep_queue(ep, req, GFP_ATOMIC))
dev_err(uac->card->dev, "%d Error!\n", __LINE__);