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| author | Takashi Iwai <tiwai@suse.de> | 2009-02-13 10:33:55 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-02-13 10:33:55 +0300 |
| commit | ae374d667a54fb5e2c9c0c4e87b206bd665f3ad6 (patch) | |
| tree | 46f68a4ca5a4663733d234190d94e7332fa81a05 /Documentation/sound | |
| parent | 20db7cb0acd0ba5a3b12f686148d670294a69366 (diff) | |
| download | linux-ae374d667a54fb5e2c9c0c4e87b206bd665f3ad6.tar.xz | |
ALSA: hda - Update documentation
Update documentation regarding codec probing; the new probe_only option
and the new probe_mask usage.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/ALSA-Configuration.txt | 3 | ||||
| -rw-r--r-- | Documentation/sound/alsa/HD-Audio.txt | 17 |
2 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt index 841a9365d5fd..012afd7afb13 100644 --- a/Documentation/sound/alsa/ALSA-Configuration.txt +++ b/Documentation/sound/alsa/ALSA-Configuration.txt @@ -757,6 +757,9 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. model - force the model name position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF) probe_mask - Bitmask to probe codecs (default = -1, meaning all slots) + When the bit 8 (0x100) is set, the lower 8 bits are used + as the "fixed" codec slots; i.e. the driver probes the + slots regardless what hardware reports back probe_only - Only probing and no codec initialization (default=off); Useful to check the initial codec status for debugging bdl_pos_adj - Specifies the DMA IRQ timing delay in samples. diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt index 8d68fff71839..99f7fbbe3e67 100644 --- a/Documentation/sound/alsa/HD-Audio.txt +++ b/Documentation/sound/alsa/HD-Audio.txt @@ -109,6 +109,13 @@ slot, pass `probe_mask=1`. For the first and the third slots, pass Since 2.6.29 kernel, the driver has a more robust probing method, so this error might happen rarely, though. +On a machine with a broken BIOS, sometimes you need to force the +driver to probe the codec slots the hardware doesn't report for use. +In such a case, turn the bit 8 (0x100) of `probe_mask` option on. +Then the rest 8 bits are passed as the codec slots to probe +unconditionally. For example, `probe_mask=0x103` will force to probe +the codec slots 0 and 1 no matter what the hardware reports. + Interrupt Handling ~~~~~~~~~~~~~~~~~~ @@ -461,6 +468,16 @@ run with `--no-upload` option, and attach the generated file. There are some other useful options. See `--help` option output for details. +When a probe error occurs or when the driver obviously assigns a +mismatched model, it'd be helpful to load the driver with +`probe_only=1` option (at best after the cold reboot) and run +alsa-info at this state. With this option, the driver won't configure +the mixer and PCM but just tries to probe the codec slot. After +probing, the proc file is available, so you can get the raw codec +information before modified by the driver. Of course, the driver +isn't usable with `probe_only=1`. But you can continue the +configuration via hwdep sysfs file if hda-reconfig option is enabled. + hda-verb ~~~~~~~~ |