Unverified Commit 7fd572e7 authored by Keyon Jie's avatar Keyon Jie Committed by Mark Brown
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ASoC: SOF: Intel: hda-stream: fix a deadlock with bus->reg_lock 



We should use irq disabled mode when read/write hda registers from
thread context, as we need to hold the same bus->reg_lock in interrupt
context hda_dsp_stream_interrupt(), otherwise, when we are holding the
lock in hda_dsp_stream_hw_free() and the interrupt arrives, we will get
deadlock in the interrupt handler.

Error logs like this:

[    5.603606]        CPU0
[    5.603606]        ----
[    5.603607]   lock(&(&bus->reg_lock)->rlock);
[    5.603608]   <Interrupt>
[    5.603609]     lock(&(&bus->reg_lock)->rlock);
[    5.603610]
                *** DEADLOCK ***

[    5.603611] 2 locks held by pulseaudio/2329:
[    5.603612]  #0: 000000005fcf26c6 (&card->mutex/1){+.+.}, at: dpcm_fe_dai_hw_free+0x2b/0x110 [snd_soc_core]
[    5.603619]  #1: 00000000ef369faf (&rtd->pcm_mutex){+.+.}, at: soc_pcm_hw_free+0x2e/0x1c0 [snd_soc_core]

The fix is simple, let's switch to use spin_lock/unlock_irq().

Reported-by: default avatarXun Zhang <xun2.zhang@intel.com>
Signed-off-by: default avatarKeyon Jie <yang.jie@linux.intel.com>
Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 6297a0dc

sound/soc/sof/intel/hda-stream.c

+2 −2
Original line number Diff line number Diff line
@@ -448,12 +448,12 @@ int hda_dsp_stream_hw_free(struct snd_sof_dev *sdev, 
	struct hdac_bus *bus = sof_to_bus(sdev);

	u32 mask = 0x1 << stream->index;



	spin_lock(&bus->reg_lock);

	spin_lock_irq(&bus->reg_lock);

	/* couple host and link DMA if link DMA channel is idle */

	if (!link_dev->link_locked)

		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR,

					SOF_HDA_REG_PP_PPCTL, mask, 0);

	spin_unlock(&bus->reg_lock);

	spin_unlock_irq(&bus->reg_lock);



	return 0;

}