ALSA : hda - bug fix on checking the supported power states of a codec
The return value of snd_hda_param_read() is -1 for an error, otherwise it's the supported power states of a codec. The supported power states is a 32-bit value. Bit 31 will be set to 1 if the codec supports EPSS, thus making "sup" negative. And the bit 28:5 is reserved as "0". So a negative value other than -1 shall be further checked. Please refer to High-Definition spec 7.3.4.12 "Supported Power States", thanks! Signed-off-by:Mengdong Lin <mengdong.lin@intel.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de>
parent
14bc9c6d
Please register or sign in to comment