From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> To: alsa-devel@alsa-project.org Cc: linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com, Bard liao <yung-chuan.liao@linux.intel.com>, Rander Wang <rander.wang@linux.intel.com>, Ranjani Sridharan <ranjani.sridharan@linux.intel.com>, Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>, Sanyog Kale <sanyog.r.kale@intel.com> Subject: [PATCH v3 14/22] soundwire: bus: fix race condition by tracking UNATTACHED transition Date: Thu, 14 Nov 2019 12:16:54 -0600 [thread overview] Message-ID: <20191114181702.22254-15-pierre-louis.bossart@linux.intel.com> (raw) In-Reply-To: <20191114181702.22254-1-pierre-louis.bossart@linux.intel.com> In previous patches, we added enumeration_ and initialization_complete fields to avoid race conditions. When streaming restarts, the Master first resumes, then requests all Slaves to renumerate/reinitialized, and then the Slave devices resume. Intel validation exposed a corner case where the Slave device may transition to D3 when streaming stops, but streaming restarts before the Master transitions to D3. In that case, the Slave status was not cleared as UNATTACHED, and the wait_for_completion will time out. The proposed solution is that when the Master clears the Slave(s) status, the reason for the Slave(s) becoming unattached is memorized. When the slave resumes, it can check if a Master-initiated re-enumeration and initialization takes place and skip the wait_for_completion() if there is no reason to wait. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> --- drivers/soundwire/bus.c | 5 ++++- drivers/soundwire/bus.h | 8 +++++++- drivers/soundwire/intel.c | 16 ++++++++++++---- 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 329f35a40649..ddc3042e15e0 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1154,7 +1154,7 @@ int sdw_handle_slave_status(struct sdw_bus *bus, } EXPORT_SYMBOL(sdw_handle_slave_status); -void sdw_clear_slave_status(struct sdw_bus *bus) +void sdw_clear_slave_status(struct sdw_bus *bus, u32 request) { struct sdw_slave *slave; int i; @@ -1174,6 +1174,9 @@ void sdw_clear_slave_status(struct sdw_bus *bus) if (slave->status != SDW_SLAVE_UNATTACHED) sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); + + /* keep track of request, used in pm_runtime resume */ + slave->unattach_request = request; } } EXPORT_SYMBOL(sdw_clear_slave_status); diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h index 4e6fb5d2f5cc..ee362472003a 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -167,6 +167,12 @@ sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) return sdw_write(slave, addr, tmp); } -void sdw_clear_slave_status(struct sdw_bus *bus); +/* + * At the moment we only track Master-initiated hw_reset. + * Additional fields can be added as needed + */ +#define SDW_UNATTACH_REQUEST_MASTER_RESET BIT(0) + +void sdw_clear_slave_status(struct sdw_bus *bus, u32 request); #endif /* __SDW_BUS_H */ diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index e3741c3afe1c..69b0c8f65ad8 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -1402,8 +1402,12 @@ static int intel_resume(struct device *dev) return ret; } - /* make sure all Slaves are tagged as UNATTACHED */ - sdw_clear_slave_status(&sdw->cdns.bus); + /* + * make sure all Slaves are tagged as UNATTACHED and provide + * reason for reinitialization + */ + sdw_clear_slave_status(&sdw->cdns.bus, + SDW_UNATTACH_REQUEST_MASTER_RESET); ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { @@ -1438,8 +1442,12 @@ static int intel_resume_runtime(struct device *dev) return ret; } - /* make sure all Slaves are tagged as UNATTACHED */ - sdw_clear_slave_status(&sdw->cdns.bus); + /* + * make sure all Slaves are tagged as UNATTACHED and provide + * reason for reinitialization + */ + sdw_clear_slave_status(&sdw->cdns.bus, + SDW_UNATTACH_REQUEST_MASTER_RESET); ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> To: alsa-devel@alsa-project.org Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>, tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, Ranjani Sridharan <ranjani.sridharan@linux.intel.com>, vkoul@kernel.org, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Sanyog Kale <sanyog.r.kale@intel.com>, Bard liao <yung-chuan.liao@linux.intel.com>, Rander Wang <rander.wang@linux.intel.com> Subject: [alsa-devel] [PATCH v3 14/22] soundwire: bus: fix race condition by tracking UNATTACHED transition Date: Thu, 14 Nov 2019 12:16:54 -0600 [thread overview] Message-ID: <20191114181702.22254-15-pierre-louis.bossart@linux.intel.com> (raw) In-Reply-To: <20191114181702.22254-1-pierre-louis.bossart@linux.intel.com> In previous patches, we added enumeration_ and initialization_complete fields to avoid race conditions. When streaming restarts, the Master first resumes, then requests all Slaves to renumerate/reinitialized, and then the Slave devices resume. Intel validation exposed a corner case where the Slave device may transition to D3 when streaming stops, but streaming restarts before the Master transitions to D3. In that case, the Slave status was not cleared as UNATTACHED, and the wait_for_completion will time out. The proposed solution is that when the Master clears the Slave(s) status, the reason for the Slave(s) becoming unattached is memorized. When the slave resumes, it can check if a Master-initiated re-enumeration and initialization takes place and skip the wait_for_completion() if there is no reason to wait. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> --- drivers/soundwire/bus.c | 5 ++++- drivers/soundwire/bus.h | 8 +++++++- drivers/soundwire/intel.c | 16 ++++++++++++---- 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 329f35a40649..ddc3042e15e0 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1154,7 +1154,7 @@ int sdw_handle_slave_status(struct sdw_bus *bus, } EXPORT_SYMBOL(sdw_handle_slave_status); -void sdw_clear_slave_status(struct sdw_bus *bus) +void sdw_clear_slave_status(struct sdw_bus *bus, u32 request) { struct sdw_slave *slave; int i; @@ -1174,6 +1174,9 @@ void sdw_clear_slave_status(struct sdw_bus *bus) if (slave->status != SDW_SLAVE_UNATTACHED) sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); + + /* keep track of request, used in pm_runtime resume */ + slave->unattach_request = request; } } EXPORT_SYMBOL(sdw_clear_slave_status); diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h index 4e6fb5d2f5cc..ee362472003a 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -167,6 +167,12 @@ sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) return sdw_write(slave, addr, tmp); } -void sdw_clear_slave_status(struct sdw_bus *bus); +/* + * At the moment we only track Master-initiated hw_reset. + * Additional fields can be added as needed + */ +#define SDW_UNATTACH_REQUEST_MASTER_RESET BIT(0) + +void sdw_clear_slave_status(struct sdw_bus *bus, u32 request); #endif /* __SDW_BUS_H */ diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index e3741c3afe1c..69b0c8f65ad8 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -1402,8 +1402,12 @@ static int intel_resume(struct device *dev) return ret; } - /* make sure all Slaves are tagged as UNATTACHED */ - sdw_clear_slave_status(&sdw->cdns.bus); + /* + * make sure all Slaves are tagged as UNATTACHED and provide + * reason for reinitialization + */ + sdw_clear_slave_status(&sdw->cdns.bus, + SDW_UNATTACH_REQUEST_MASTER_RESET); ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { @@ -1438,8 +1442,12 @@ static int intel_resume_runtime(struct device *dev) return ret; } - /* make sure all Slaves are tagged as UNATTACHED */ - sdw_clear_slave_status(&sdw->cdns.bus); + /* + * make sure all Slaves are tagged as UNATTACHED and provide + * reason for reinitialization + */ + sdw_clear_slave_status(&sdw->cdns.bus, + SDW_UNATTACH_REQUEST_MASTER_RESET); ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { -- 2.20.1 _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
next prev parent reply other threads:[~2019-11-14 18:17 UTC|newest] Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-14 18:16 [PATCH v3 00/22] soundwire: code hardening and suspend-resume support Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 01/22] soundwire: intel/cadence: fix timeouts in MSI mode Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 02/22] soundwire: bus: fix race condition with probe_complete signaling Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 03/22] soundwire: bus: add PM/no-PM versions of read/write functions Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 04/22] soundwire: bus: write Slave Device Number without runtime_pm Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 05/22] soundwire: intel: add helpers for link power down and shim wake Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 06/22] soundwire: intel: Add basic power management support Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 07/22] soundwire: intel: add pm_runtime support Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 08/22] soundwire: intel: reset pm_runtime status during system resume Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 09/22] soundwire: bus: add helper to reset Slave status to UNATTACHED Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 10/22] soundwire: intel: call helper to reset Slave states on resume Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 11/22] soundwire: bus: check first if Slaves become UNATTACHED Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 12/22] soundwire: bus: fix race condition with enumeration_complete signaling Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 13/22] soundwire: bus: fix race condition with initialization_complete signaling Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` Pierre-Louis Bossart [this message] 2019-11-14 18:16 ` [alsa-devel] [PATCH v3 14/22] soundwire: bus: fix race condition by tracking UNATTACHED transition Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 15/22] soundwire: intel: disable pm_runtime when removing a master Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 16/22] soundwire: bus: disable pm_runtime in sdw_slave_delete Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 17/22] soundwire: stream: remove redundant pr_err traces Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 18/22] soundwire: stream: update state machine and add state checks Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:16 ` [PATCH v3 19/22] soundwire: stream: only prepare stream when it is configured Pierre-Louis Bossart 2019-11-14 18:16 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:17 ` [PATCH v3 20/22] soundwire: stream: do not update parameters during DISABLED-PREPARED transition Pierre-Louis Bossart 2019-11-14 18:17 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:17 ` [PATCH v3 21/22] soundwire: intel: reinitialize IP+DSP in .prepare(), but only when resuming Pierre-Louis Bossart 2019-11-14 18:17 ` [alsa-devel] " Pierre-Louis Bossart 2019-11-14 18:17 ` [PATCH v3 22/22] soundwire: intel: pm_runtime idle scheduling Pierre-Louis Bossart 2019-11-14 18:17 ` [alsa-devel] " Pierre-Louis Bossart
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