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

[ Upstream commit 6b37bd78d3 ]

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.

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: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Joshua Frkuska 2018-06-21 17:22:48 +02:00 committed by Greg Kroah-Hartman
parent dc126a1e5f
commit 224c0d0894
1 changed files with 5 additions and 1 deletions
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6
drivers/usb/gadget/function/u_audio.c
View File

@ -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__);