• Stephen Warren's avatar
    ASoC: free jack GPIOs before the sound card is freed · e1d4d3c8
    Stephen Warren authored
    This is the same change as commit fb6b8e71 "ASoC: tegra: free jack
    GPIOs before the sound card is freed", but applied to all other ASoC
    machine drivers where code inspection indicates the same problem exists.
    
    That commit's description is:
    ==========
    snd_soc_jack_add_gpios() schedules a work queue item to poll the GPIO to
    generate an initial jack status report. If sound card initialization
    fails, that work item needs to be cancelled, so it doesn't run after the
    card has been freed. Specifically, freeing the card calls
    snd_jack_dev_free() which calls snd_jack_dev_disconnect() which sets
    jack->input_dev = NULL, and input_dev is used by snd_jack_report(), which
    is called from the work queue item.
    
    snd_soc_jack_free_gpios() cancels the work item. The Tegra ASoC machine
    drivers do call this function in the platform driver remove() callback.
    However, this happens after the sound card is freed, at least when the
    card is freed due to errors late during snd_soc_instantiate_card(). This
    leaves a window where the work item can execute after the card is freed.
    In next-20140522, sound card initialization does fail for unrelated
    reasons, and hits the problem described above.
    
    To solve this, fix the Tegra ASoC machine drivers to clean up the Jack
    GPIOs during the snd_soc_card's .remove() callback, which is executed
    before the overall card object is freed. also, guard the cleanup call
    based on whether we actually setup up the GPIOs in the first place.
    Ideally, we'd do the cleanup in a struct snd_soc_dai_link .fini/remove
    function to match where the GPIOs get set up. However, there is no such
    callback.
    ==========
    
    Note that I have not even compile-tested this in most cases, since most
    of the drivers rely on specific mach-* support I don't have enabled, and
    don't support COMPILE_TEST. Testing by the relevant board maintainers
    would be useful.
    Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
    Signed-off-by: default avatarMark Brown <broonie@linaro.org>
    e1d4d3c8
smartq_wm8987.c 6.69 KB