From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Sakamoto Subject: Re: [PATCH] ALSA: usb-audio: Fix quirks code is not called Date: Mon, 18 Jul 2016 14:35:05 +0900 Message-ID: <578C6A89.6000008@sakamocchi.jp> References: <20160717161615.2399-1-k@oikw.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp-proxy002.phy.lolipop.jp (smtp-proxy002.phy.lolipop.jp [157.7.104.43]) by alsa0.perex.cz (Postfix) with ESMTP id CC160265721 for ; Mon, 18 Jul 2016 07:35:10 +0200 (CEST) In-Reply-To: <20160717161615.2399-1-k@oikw.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Kazuki Oikawa , Takashi Iwai Cc: alsa-devel@alsa-project.org, nekomatu+linux@gmail.com List-Id: alsa-devel@alsa-project.org Hi, On Jul 18 2016 01:16, Kazuki Oikawa wrote: > snd_usb_{set_interface,ctl_msg}_quirk checks chip->usb_id to need > calling a quirks code. But existed code path that not calling > dev_set_drvdata in usb_audio_probe. > > Signed-off-by: Kazuki Oikawa > Fixes: 79289e24194a ("ALSA: usb-audio: Refer to chip->usb_id for quirks and MIDI creation") > --- > sound/usb/card.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/sound/usb/card.c b/sound/usb/card.c > index 3fc63583a537..2d493501b7f6 100644 > --- a/sound/usb/card.c > +++ b/sound/usb/card.c > @@ -552,7 +552,6 @@ static int usb_audio_probe(struct usb_interface *intf, > goto __error; > } > chip = usb_chip[i]; > - dev_set_drvdata(&dev->dev, chip); > atomic_inc(&chip->active); /* avoid autopm */ > break; > } > @@ -578,6 +577,7 @@ static int usb_audio_probe(struct usb_interface *intf, > goto __error; > } > } > + dev_set_drvdata(&dev->dev, chip); > > /* > * For devices with more than one control interface, we assume the Reviewed-by: Takashi Sakamoto Tested-by: Takashi Sakamoto Let me describe supplemental comments. This bug affects all of USB devices which take USB subsystem to call an implementation of struct usb_driver.probe() in snd-usb-audio (=usb_audio_probe()) just one time. In this case, dev_set_drvdata() is not called at first call of usb_audio_probe(), then dev_get_drvdata() returns NULL. As a result, some quirks are not handled. snd_usb_set_interface_quirk() and snd_usb_set_interface_quirk() returns immediately without enough operations. This brings regressions to some models. As long as I asked to Mr.Oikawa in this morning, below models are affected. * Playback Design * TEAC * Marantz * Denon * Zoom R16/24 I tested with EMU 0404 USB. This model has no quirks related to above functions, but it brings just one call of usb_audio_probe(). Then, without this patch, I can see dev_get_drvdata() always returns NULL whole lifetime of usb device instance. (But even with this patch, in a call of snd_usb_audio_free(), dev_get_drvdata() returns NULL before a call of dev_set_devdata(NULL), against my expectation. I don't know why...) This patch should go for 4.8 merge window. Regards Takashi Sakamoto