[alsa-devel] [PATCH 2/3] sound: enable interrupt after dma buffer initialization

[Takashi Iwai]

On Mon, 10 Sep 2018 23:21:50 +0200,
Yu Zhao wrote:
> 
> In snd_hdac_bus_init_chip(), we enable interrupt before
> snd_hdac_bus_init_cmd_io() initializing dma buffers. If irq has
> been acquired and irq handler uses the dma buffer, kernel may crash
> when interrupt comes in.
> 
> Fix the problem by postponing enabling irq after dma buffer
> initialization. And warn once on null dma buffer pointer during the
> initialization.
> 
> Signed-off-by: Yu Zhao <yuzhao at google.com>

Looks good to me.

Reviewed-by: Takashi Iwai <tiwai at suse.de>


BTW, the reason why this hasn't been hit on the legacy HD-audio driver
is that we allocate usually with MSI, so the irq is isolated.

Any reason that Intel SKL driver doesn't use MST?


thanks,

Takashi