[PATCH 1/3] ASoC: SOF: debug: conditionally bump runtime_pm counter on exceptions

From: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
To: lgirdwood@gmail.com, broonie@kernel.org
Cc: alsa-devel@alsa-project.org,
	pierre-louis.bossart@linux.intel.com,
	ranjani.sridharan@linux.intel.com, kai.vehmanen@linux.intel.com,
	daniel.baluta@nxp.com
Subject: [PATCH 1/3] ASoC: SOF: debug: conditionally bump runtime_pm counter on exceptions
Date: Fri, 12 May 2023 13:33:13 +0300	[thread overview]
Message-ID: <20230512103315.8921-2-peter.ujfalusi@linux.intel.com> (raw)
In-Reply-To: <20230512103315.8921-1-peter.ujfalusi@linux.intel.com>

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

When a firmware IPC error happens during a pm_runtime suspend, we
ignore the error and suspend anyways. However, the code
unconditionally increases the runtime_pm counter. This results in a
confusing configuration where the code will suspend, resume but never
suspend again due to the use of pm_runtime_get_noresume().

The intent of the counter increase was to prevent entry in D3, but if
that transition to D3 is already started it cannot be stopped. In
addition, there's no point in that case in trying to prevent anything,
the firmware error is handled and the next resume will re-initialize
the firmware completely.

This patch changes the logic to prevent suspend when the device is
pm_runtime active and has a use_count > 0.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
---
 sound/soc/sof/debug.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/sof/debug.c b/sound/soc/sof/debug.c
index b42b5982cbbc..d547318e0d32 100644
--- a/sound/soc/sof/debug.c
+++ b/sound/soc/sof/debug.c
@@ -438,8 +438,8 @@ void snd_sof_handle_fw_exception(struct snd_sof_dev *sdev, const char *msg)
 		/* should we prevent DSP entering D3 ? */
 		if (!sdev->ipc_dump_printed)
 			dev_info(sdev->dev,
-				 "preventing DSP entering D3 state to preserve context\n");
-		pm_runtime_get_noresume(sdev->dev);
+				 "Attempting to prevent DSP from entering D3 state to preserve context\n");
+		pm_runtime_get_if_in_use(sdev->dev);
 	}
 
 	/* dump vital information to the logs */
-- 
2.40.1

