From: Joshua Frkuska Date: Thu, 21 Jun 2018 15:22:48 +0000 (+0200) Subject: usb: gadget: u_audio: update hw_ptr in iso_complete after data copied X-Git-Tag: v4.18-rc7~15^2~4^2~13 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=6b37bd78d30c890e575a1bda22978d1d2a233362;p=linux.git usb: gadget: u_audio: update hw_ptr in iso_complete after data copied 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: 132fcb460839 ("usb: gadget: Add Audio Class 2.0 Driver") Signed-off-by: Joshua Frkuska Signed-off-by: Eugeniu Rosca Signed-off-by: Felipe Balbi --- diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c index c0a65e110fc9..4c6df7130891 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -143,7 +143,6 @@ 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); @@ -168,6 +167,11 @@ 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__);