From 224c0d0894ff7c3e85add1ce02a523d7f49cfdda Mon Sep 17 00:00:00 2001 From: Joshua Frkuska Date: Thu, 21 Jun 2018 17:22:48 +0200 Subject: [PATCH] usb: gadget: u_audio: update hw_ptr in iso_complete after data copied [ Upstream commit 6b37bd78d30c890e575a1bda22978d1d2a233362 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/u_audio.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c index 429d7928b7c9..725593f7da9b 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -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__); -- 2.20.1