From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 1/5] allow up to 32 PCM devices Date: Thu, 13 May 2010 10:21:26 +0800 Message-ID: <20100513022126.GA13559@localhost> References: <20100512013015.752623810@intel.com> <20100512015713.762299923@intel.com> <20100512083950.GB11001@localhost> <4BEA80F1.7040600@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by alsa0.perex.cz (Postfix) with ESMTP id E61232464F for ; Thu, 13 May 2010 04:21:30 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: "alsa-devel@alsa-project.org" , Clemens Ladisch List-Id: alsa-devel@alsa-project.org On Wed, May 12, 2010 at 06:55:09PM +0800, Takashi Iwai wrote: > At Wed, 12 May 2010 12:20:33 +0200, > Clemens Ladisch wrote: > > > > Takashi Iwai wrote: > > > Wu Fengguang wrote: > > > > > Jaroslav Kysela wrote: > > > > > > I don't agree to have only 4 slots for soundcards in the static minor > > > > > > numbering. Maybe the driver should be converted to use subdevices or we > > > > > > might drop the static minor number allocation at all (it might have only > > > > > > impact for old distros). > > > > > > > > Jaroslav, will there be so many sound cards in one system? > > > > > > In the old time, yes. Now we have less and less PCI slots. > > > In theory, we may have lots of USB audio devices, though :) > > > > I implemented CONFIG_SND_DYNAMIC_MINORS because people had been asking > > for more than eight cards. (And by now I have lots of cards too, > > although my computer probably isn't very typical.) > > > > Anyway, static numbering is needed only for systems without udev/devfs, > > and there we shouldn't change it for backwards compatibility. The HDA > > driver already requires kernels >= 2.6, so I don't see a problem with > > requiring CONFIG_SND_DYNAMIC_MINORS to get all HDMI outputs. > > Right. We can make it dependent. > Like this? config SND_HDA_CODEC_INTELHDMI bool "Build INTEL HDMI HD-audio codec support" + select SND_DYNAMIC_MINORS default y That will effectively turn on CONFIG_SND_DYNAMIC_MINORS by default (distribution kernels will have to enable it). Another backwards compatible solution is to fall back to the two reserved values. This makes me a bit more comfortable :) --- drm-intel.orig/include/sound/minors.h 2010-05-13 10:06:52.000000000 +0800 +++ drm-intel/include/sound/minors.h 2010-05-13 10:10:06.000000000 +0800 @@ -35,7 +35,9 @@ #define SNDRV_MINOR_TIMER (SNDRV_MINOR_GLOBAL + 1 * 32) #ifndef CONFIG_SND_DYNAMIC_MINORS - /* 2 - 3 (reserved) */ + +#define SNDRV_MINOR_BACKUP1 2 +#define SNDRV_MINOR_BACKUP2 3 #define SNDRV_MINOR_HWDEP 4 /* 4 - 7 */ #define SNDRV_MINOR_RAWMIDI 8 /* 8 - 15 */ #define SNDRV_MINOR_PCM_PLAYBACK 16 /* 16 - 23 */ --- drm-intel.orig/sound/core/sound.c 2010-05-13 10:06:04.000000000 +0800 +++ drm-intel/sound/core/sound.c 2010-05-13 10:11:19.000000000 +0800 @@ -269,8 +269,14 @@ int snd_register_device_for_dev(int type minor = snd_find_free_minor(); #else minor = snd_kernel_minor(type, card, dev); - if (minor >= 0 && snd_minors[minor]) - minor = -EBUSY; + if (minor >= 0) { + if (snd_minors[minor]) + minor = SNDRV_MINOR_BACKUP1; + if (snd_minors[minor]) + minor = SNDRV_MINOR_BACKUP2; + if (snd_minors[minor]) + minor = -EBUSY; + } #endif if (minor < 0) { mutex_unlock(&sound_mutex); Thanks, Fengguang