ASoC: SOF: ipc: fix a race, leading to IPC timeouts
Currently on all supported platforms the IPC IRQ thread first signals the sender when an IPC response is received from the DSP, then unmasks the IPC interrupt. Those actions are performed without holding any locks, so the thread can be interrupted between them. IPC timeouts have been observed in such scenarios: if the sender is woken up and it proceeds with sending the next message without unmasking the IPC interrupt, it can miss the next response. This patch takes a spin-lock to prevent the IRQ thread from being preempted at that point. It also makes sure, that the next IPC transmission by the host cannot take place before the IRQ thread has finished updating all the required IPC registers. Fixes: 53e0c72d ("ASoC: SOF: Add support for IPC IO between DSP and Host") Reviewed-by:Takashi Iwai <tiwai@suse.de> Signed-off-by:
Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com> Signed-off-by:
Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by:
Mark Brown <broonie@kernel.org>
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