From 18236370a098428d7639686daa36584d0d363c9e Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Mon, 14 Jun 2021 13:08:13 -0500 Subject: [PATCH] ASoC: rt711-sdw: fix race condition on system suspend MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In previous commits we cancelled deferred work, but there is still a window of time where a new interrupt could result in new deferred work executed after the link is disabled, leading to an IO error. While we did not see this IO error on RT711-based platforms, the code pattern is similar to the RT700 case where the IO error was noted, so the fix is added for consistency. This patch uses an 'disable_irq_lock' mutex to prevent new interrupts from happening after the start of the system suspend. The choice of a mutex v. a spinlock is mainly due to the time required to clear interrupts, which requires a command to be transmitted by the SoundWire host IP and acknowledged with an interrupt. The 'interrupt_callback' routine is also not meant to be called from an interrupt context. An additional 'disable_irq' flag prevents race conditions where the status changes before the interrupts are disabled, but the workqueue handling status changes is scheduled after the completion of the system suspend. On resume the interrupts are re-enabled already by the io_init routine so we only clear the flag. BugLink: https://github.com/thesofproject/linux/issues/2943 Fixes: 501ef013390b ('ASoC: rt711: wait for the delayed work to finish when the system suspends') Signed-off-by: Pierre-Louis Bossart Reviewed-by: Bard Liao Reviewed-by: Péter Ujfalusi Link: https://lore.kernel.org/r/20210614180815.153711-4-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown --- sound/soc/codecs/rt711-sdw.c | 34 ++++++++++++++++++++++++++++++++-- sound/soc/codecs/rt711.c | 4 ++++ sound/soc/codecs/rt711.h | 2 ++ 3 files changed, 38 insertions(+), 2 deletions(-) diff --git a/sound/soc/codecs/rt711-sdw.c b/sound/soc/codecs/rt711-sdw.c index 15299084429f2..bda2cc9439c98 100644 --- a/sound/soc/codecs/rt711-sdw.c +++ b/sound/soc/codecs/rt711-sdw.c @@ -423,10 +423,12 @@ static int rt711_interrupt_callback(struct sdw_slave *slave, dev_dbg(&slave->dev, "%s control_port_stat=%x", __func__, status->control_port); - if (status->control_port & 0x4) { + mutex_lock(&rt711->disable_irq_lock); + if (status->control_port & 0x4 && !rt711->disable_irq) { mod_delayed_work(system_power_efficient_wq, &rt711->jack_detect_work, msecs_to_jiffies(250)); } + mutex_unlock(&rt711->disable_irq_lock); return 0; } @@ -493,6 +495,34 @@ static int __maybe_unused rt711_dev_suspend(struct device *dev) return 0; } +static int __maybe_unused rt711_dev_system_suspend(struct device *dev) +{ + struct rt711_priv *rt711 = dev_get_drvdata(dev); + struct sdw_slave *slave = dev_to_sdw_dev(dev); + int ret; + + if (!rt711->hw_init) + return 0; + + /* + * prevent new interrupts from being handled after the + * deferred work completes and before the parent disables + * interrupts on the link + */ + mutex_lock(&rt711->disable_irq_lock); + rt711->disable_irq = true; + ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, + SDW_SCP_INT1_IMPL_DEF, 0); + mutex_unlock(&rt711->disable_irq_lock); + + if (ret < 0) { + /* log but don't prevent suspend from happening */ + dev_dbg(&slave->dev, "%s: could not disable imp-def interrupts\n:", __func__); + } + + return rt711_dev_suspend(dev); +} + #define RT711_PROBE_TIMEOUT 5000 static int __maybe_unused rt711_dev_resume(struct device *dev) @@ -524,7 +554,7 @@ regmap_sync: } static const struct dev_pm_ops rt711_pm = { - SET_SYSTEM_SLEEP_PM_OPS(rt711_dev_suspend, rt711_dev_resume) + SET_SYSTEM_SLEEP_PM_OPS(rt711_dev_system_suspend, rt711_dev_resume) SET_RUNTIME_PM_OPS(rt711_dev_suspend, rt711_dev_resume, NULL) }; diff --git a/sound/soc/codecs/rt711.c b/sound/soc/codecs/rt711.c index 9f5b2dc16c54f..4dbfa7b8680e4 100644 --- a/sound/soc/codecs/rt711.c +++ b/sound/soc/codecs/rt711.c @@ -1166,6 +1166,8 @@ int rt711_init(struct device *dev, struct regmap *sdw_regmap, rt711->sdw_regmap = sdw_regmap; rt711->regmap = regmap; + mutex_init(&rt711->disable_irq_lock); + /* * Mark hw_init to false * HW init will be performed when device reports present @@ -1190,6 +1192,8 @@ int rt711_io_init(struct device *dev, struct sdw_slave *slave) { struct rt711_priv *rt711 = dev_get_drvdata(dev); + rt711->disable_irq = false; + if (rt711->hw_init) return 0; diff --git a/sound/soc/codecs/rt711.h b/sound/soc/codecs/rt711.h index ca0f581feec78..2af4676314351 100644 --- a/sound/soc/codecs/rt711.h +++ b/sound/soc/codecs/rt711.h @@ -25,6 +25,8 @@ struct rt711_priv { struct work_struct calibration_work; struct mutex calibrate_mutex; /* for headset calibration */ int jack_type, jd_src; + struct mutex disable_irq_lock; /* imp-def irq lock protection */ + bool disable_irq; }; struct sdw_stream_data { -- 2.30.2