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ALSA: hda - Limit the amp value to write

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Check the amp max value at put callbacks and set the upper limit
so that the driver won't write any invalid value over the defined
range.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2010-07-08 18:40:37 +02:00
parent 3507e2a8f1
commit afbd9b8448
1 changed files with 21 additions and 11 deletions
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32
sound/pci/hda/hda_codec.c
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@ -1539,6 +1539,17 @@ void snd_hda_codec_resume_amp(struct hda_codec *codec)
EXPORT_SYMBOL_HDA(snd_hda_codec_resume_amp);
#endif /* SND_HDA_NEEDS_RESUME */
static u32 get_amp_max_value(struct hda_codec *codec, hda_nid_t nid, int dir,
unsigned int ofs)
{
u32 caps = query_amp_caps(codec, nid, dir);
/* get num steps */
caps = (caps & AC_AMPCAP_NUM_STEPS) >> AC_AMPCAP_NUM_STEPS_SHIFT;
if (ofs < caps)
caps -= ofs;
return caps;
}
/**
* snd_hda_mixer_amp_volume_info - Info callback for a standard AMP mixer
*
@ -1553,23 +1564,17 @@ int snd_hda_mixer_amp_volume_info(struct snd_kcontrol *kcontrol,
u8 chs = get_amp_channels(kcontrol);
int dir = get_amp_direction(kcontrol);
unsigned int ofs = get_amp_offset(kcontrol);
u32 caps;
caps = query_amp_caps(codec, nid, dir);
/* num steps */
caps = (caps & AC_AMPCAP_NUM_STEPS) >> AC_AMPCAP_NUM_STEPS_SHIFT;
if (!caps) {
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = chs == 3 ? 2 : 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = get_amp_max_value(codec, nid, dir, ofs);
if (!uinfo->value.integer.max) {
printk(KERN_WARNING "hda_codec: "
"num_steps = 0 for NID=0x%x (ctl = %s)\n", nid,
kcontrol->id.name);
return -EINVAL;
}
if (ofs < caps)
caps -= ofs;
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = chs == 3 ? 2 : 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = caps;
return 0;
}
EXPORT_SYMBOL_HDA(snd_hda_mixer_amp_volume_info);
@ -1594,8 +1599,13 @@ update_amp_value(struct hda_codec *codec, hda_nid_t nid,
int ch, int dir, int idx, unsigned int ofs,
unsigned int val)
{
unsigned int maxval;
if (val > 0)
val += ofs;
maxval = get_amp_max_value(codec, nid, dir, ofs);
if (val > maxval)
val = maxval;
return snd_hda_codec_amp_update(codec, nid, ch, dir, idx,
HDA_AMP_VOLMASK, val);
}