[PATCH] ASoC: fsl_xcvr: disable all interrupts when suspend happens

There is an unhandled interrupt after suspend, which cause endless
interrupt when system resume, so system may hang.

Disable all interrupts in runtime suspend callback to avoid above
issue.

Signed-off-by: Shengjiu Wang <redacted>
---
 sound/soc/fsl/fsl_xcvr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sound/soc/fsl/fsl_xcvr.c b/sound/soc/fsl/fsl_xcvr.c
index df7c189d97dd..37b4fdb236ee 100644
--- a/sound/soc/fsl/fsl_xcvr.c
+++ b/sound/soc/fsl/fsl_xcvr.c

@@ -1233,6 +1233,11 @@ static __maybe_unused int fsl_xcvr_runtime_suspend(struct device *dev)
 	struct fsl_xcvr *xcvr = dev_get_drvdata(dev);
 	int ret;
 
+	ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_IER0,
+				 FSL_XCVR_IRQ_EARC_ALL, 0);
+	if (ret < 0)
+		dev_err(dev, "Failed to clear IER0: %d\n", ret);
+
 	/* Assert M0+ reset */
 	ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_CTRL,
 				 FSL_XCVR_EXT_CTRL_CORE_RESET,

-- 
2.27.0

Hi Shengjiu,

On Fri, Jun 18, 2021 at 7:10 AM Shengjiu Wang [off-list ref] wrote:

There is an unhandled interrupt after suspend, which cause endless
interrupt when system resume, so system may hang.

Disable all interrupts in runtime suspend callback to avoid above
issue.

Fixe tag?

The operations in _suspend() are usually balanced with the ones in _resume().

Shouldn't you enable the interrupts in resume() then?

I see that the interrupts are currently enabled inside fsl_xcvr_prepare().

Hi Fabio

On Fri, Jun 18, 2021 at 7:21 PM Fabio Estevam [off-list ref] wrote:

Hi Shengjiu,

On Fri, Jun 18, 2021 at 7:10 AM Shengjiu Wang [off-list ref] wrote:

quoted

There is an unhandled interrupt after suspend, which cause endless
interrupt when system resume, so system may hang.

Disable all interrupts in runtime suspend callback to avoid above
issue.

Fixe tag?

ok, I will add it.

quoted

+       ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_IER0,
+                                FSL_XCVR_IRQ_EARC_ALL, 0);
+       if (ret < 0)
+               dev_err(dev, "Failed to clear IER0: %d\n", ret);
+

The operations in _suspend() are usually balanced with the ones in _resume().

Shouldn't you enable the interrupts in resume() then?

No,  as you said below, the interrupts are enabled in fsl_xcvr_prepare().
so this change should not block anything.

I see that the interrupts are currently enabled inside fsl_xcvr_prepare().

On Fri, Jun 18, 2021 at 07:30:25PM +0800, Shengjiu Wang wrote:

On Fri, Jun 18, 2021 at 7:21 PM Fabio Estevam [off-list ref] wrote:

quoted

The operations in _suspend() are usually balanced with the ones in _resume().

quoted

Shouldn't you enable the interrupts in resume() then?

No,  as you said below, the interrupts are enabled in fsl_xcvr_prepare().
so this change should not block anything.

Might be worth a comment explaining why there's the asymmetry.

On Fri, 18 Jun 2021 17:51:16 +0800, Shengjiu Wang wrote:

There is an unhandled interrupt after suspend, which cause endless
interrupt when system resume, so system may hang.

Disable all interrupts in runtime suspend callback to avoid above
issue.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl_xcvr: disable all interrupts when suspend happens
      commit: ea837090b388245744988083313f6e9c7c9b9699

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark