From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ea0-f170.google.com ([209.85.215.170]:48350 "EHLO mail-ea0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752071AbaAMSaz (ORCPT ); Mon, 13 Jan 2014 13:30:55 -0500 Received: by mail-ea0-f170.google.com with SMTP id k10so3482441eaj.15 for ; Mon, 13 Jan 2014 10:30:54 -0800 (PST) Message-ID: <52D43125.9010601@googlemail.com> Date: Mon, 13 Jan 2014 19:32:05 +0100 From: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: linux-media@vger.kernel.org Subject: Re: [PATCH 2/2] em28xx: fix check for audio only usb interfaces when changing the usb alternate setting References: <1389447750-2642-1-git-send-email-fschaefer.oss@googlemail.com> <1389447750-2642-2-git-send-email-fschaefer.oss@googlemail.com> <20140112153729.6f87cd2e@samsung.com> In-Reply-To: <20140112153729.6f87cd2e@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: On 12.01.2014 18:37, Mauro Carvalho Chehab wrote: > Em Sat, 11 Jan 2014 14:42:30 +0100 > Frank Schäfer escreveu: > >> Previously, we've been assuming that the video endpoints are always at usb >> interface 0. Hence, if vendor audio endpoints are provided at a separate >> interface, they were supposed to be at interface number > 0. >> Instead of checking for (interface number > 0) to determine if an interface is a >> pure audio interface, dev->is_audio_only should be checked. >> >> Signed-off-by: Frank Schäfer >> --- >> drivers/media/usb/em28xx/em28xx-audio.c | 15 +++++++++++++-- >> 1 Datei geändert, 13 Zeilen hinzugefügt(+), 2 Zeilen entfernt(-) >> >> diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c >> index b2ae954..18b745f 100644 >> --- a/drivers/media/usb/em28xx/em28xx-audio.c >> +++ b/drivers/media/usb/em28xx/em28xx-audio.c >> @@ -243,11 +243,22 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream) >> } >> >> runtime->hw = snd_em28xx_hw_capture; >> - if ((dev->alt == 0 || dev->ifnum) && dev->adev.users == 0) { >> - if (dev->ifnum) >> + if (dev->adev.users == 0 && (dev->alt == 0 || dev->is_audio_only)) { >> + if (dev->is_audio_only) >> + /* vendor audio is on a separate interface */ >> dev->alt = 1; >> else >> + /* vendor audio is on the same interface as video */ >> dev->alt = 7; >> + /* >> + * FIXME: The intention seems to be to select the alt >> + * setting with the largest wMaxPacketSize for the video >> + * endpoint. >> + * At least dev->alt and dev->dvb_alt_isoc should be >> + * used instead, but we should probably not touch it at >> + * all if it is already >0, because wMaxPacketSize of >> + * the audio endpoints seems to be the same for all. >> + */ > Actually, it should take into account only the analog case, since, in > digital mode, the audio comes via the MPEG stream instead. Yes, of course you are absolutely right. I will fix the comment. > > Ok, it makes sense to return -EBUSY if one tries to use it while using > DVB. > >> >> dprintk("changing alternate number on interface %d to %d\n", >> dev->ifnum, dev->alt); >