• Mohan Kumar's avatar
    ALSA: hda: Avoid unsol event during RPM suspending · 6ddc2f74
    Mohan Kumar authored
    There is a corner case with unsol event handling during codec runtime
    suspending state. When the codec runtime suspend call initiated, the
    codec->in_pm atomic variable would be 0, currently the codec runtime
    suspend function calls snd_hdac_enter_pm() which will just increments
    the codec->in_pm atomic variable. Consider unsol event happened just
    after this step and before snd_hdac_leave_pm() in the codec runtime
    suspend function. The snd_hdac_power_up_pm() in the unsol event
    flow in hdmi_present_sense_via_verbs() function would just increment
    the codec->in_pm atomic variable without calling pm_runtime_get_sync
    function.
    
    As codec runtime suspend flow is already in progress and in parallel
    unsol event is also accessing the codec verbs, as soon as codec
    suspend flow completes and clocks are  switched off before completing
    the unsol event handling as both functions doesn't wait for each other.
    This will result in below errors
    
    [  589.428020] tegra-hda 3510000.hda: azx_get_response timeout, switching
    to polling mode: last cmd=0x505f2f57
    [  589.428344] tegra-hda 3510000.hda: spurious response 0x80000074:0x5,
    last cmd=0x505f2f57
    [  589.428547] tegra-hda 3510000.hda: spurious response 0x80000065:0x5,
    last cmd=0x505f2f57
    
    To avoid this, the unsol event flow should not perform any codec verb
    related operations during RPM_SUSPENDING state.
    Signed-off-by: default avatarMohan Kumar <mkumard@nvidia.com>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20220329155940.26331-1-mkumard@nvidia.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    6ddc2f74
patch_hdmi.c 123 KB