[PATCH for-4.15] ASoC: rt5514: don't assume rt5514 component was "attached"

[Brian Norris]

+ others

On Fri, Dec 15, 2017 at 05:12:30PM -0800, Brian Norris wrote:
> I've found that on Google's "Kevin" Chromebook, the rt5514 codec might
> not be set up completely, yet its device is still present, and therefore
> its PM suspend/resume is called. This hits a NULL pointer exception,
> since we never had the chance to set our drvdata pointer.
> 
> This resolves crashes seen when trying to resume my system.
> 
> Fixes: e9c50aa6bd39 ("ASoC: rt5514-spi: check irq status to schedule data copy in resume function")
> Signed-off-by: Brian Norris <briannorris at chromium.org>
> ---
> This is a v4.15-rc1 regression

I see that this is probably a bug on its own, which should be fixed on
its own (e.g., with the $subject patch), but FYI I was also pointed at
this patch, which also "resolves" this problem by fixing the rt5514 DAI
setup:

https://patchwork.kernel.org/patch/10067725/
[PATCH] ASoC: rockchip: Use dummy_dai for rt5514 dsp dailink

Would be nice to see it get handled too, possibly in 4.15 as well (I
think that's a regression too?).

Brian

> 
>  sound/soc/codecs/rt5514-spi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/codecs/rt5514-spi.c b/sound/soc/codecs/rt5514-spi.c
> index 2df91db765ac..9255afcf2c3a 100644
> --- a/sound/soc/codecs/rt5514-spi.c
> +++ b/sound/soc/codecs/rt5514-spi.c
> @@ -482,7 +482,7 @@ static int __maybe_unused rt5514_resume(struct device *dev)
>  	if (device_may_wakeup(dev))
>  		disable_irq_wake(irq);
>  
> -	if (rt5514_dsp->substream) {
> +	if (rt5514_dsp && rt5514_dsp->substream) {
>  		rt5514_spi_burst_read(RT5514_IRQ_CTRL, (u8 *)&buf, sizeof(buf));
>  		if (buf[0] & RT5514_IRQ_STATUS_BIT)
>  			rt5514_schedule_copy(rt5514_dsp);
> -- 
> 2.15.1.504.g5279b80103-goog
>