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 02/10] soundwire: bus: fix race condition with enumeration_complete signaling Date: Tue, 14 Jan 2020 18:08:36 -0600 [thread overview] Message-ID: <20200115000844.14695-3-pierre-louis.bossart@linux.intel.com> (raw) In-Reply-To: <20200115000844.14695-1-pierre-louis.bossart@linux.intel.com> This patch adds the signaling needed for Slave drivers to wait until the enumeration completes so that race conditions when issuing read/write commands are avoided. The calls for wait_for_completion() will be added in codec drivers in follow-up patches. The order between init_completion() and complete() is deterministic, the Slave is marked as UNATTACHED either during a Master-initiated HardReset, or when the hardware detects the Slave no longer reports as ATTACHED. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> --- drivers/soundwire/bus.c | 20 ++++++++++++++++++++ drivers/soundwire/slave.c | 1 + 2 files changed, 21 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4980dfd6f3a3..a2267c3a1d2d 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -610,6 +610,26 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, enum sdw_slave_status status) { mutex_lock(&slave->bus->bus_lock); + + dev_vdbg(&slave->dev, + "%s: changing status slave %d status %d new status %d\n", + __func__, slave->dev_num, slave->status, status); + + if (status == SDW_SLAVE_UNATTACHED) { + dev_dbg(&slave->dev, + "%s: initializing completion for Slave %d\n", + __func__, slave->dev_num); + + init_completion(&slave->enumeration_complete); + + } else if ((status == SDW_SLAVE_ATTACHED) && + (slave->status == SDW_SLAVE_UNATTACHED)) { + dev_dbg(&slave->dev, + "%s: signaling completion for Slave %d\n", + __func__, slave->dev_num); + + complete(&slave->enumeration_complete); + } slave->status = status; mutex_unlock(&slave->bus->bus_lock); } diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index 08db0488e02d..e767a78066ee 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -46,6 +46,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->dev.of_node = of_node_get(to_of_node(fwnode)); slave->bus = bus; slave->status = SDW_SLAVE_UNATTACHED; + init_completion(&slave->enumeration_complete); slave->dev_num = 0; init_completion(&slave->probe_complete); slave->probed = false; -- 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 02/10] soundwire: bus: fix race condition with enumeration_complete signaling Date: Tue, 14 Jan 2020 18:08:36 -0600 [thread overview] Message-ID: <20200115000844.14695-3-pierre-louis.bossart@linux.intel.com> (raw) In-Reply-To: <20200115000844.14695-1-pierre-louis.bossart@linux.intel.com> This patch adds the signaling needed for Slave drivers to wait until the enumeration completes so that race conditions when issuing read/write commands are avoided. The calls for wait_for_completion() will be added in codec drivers in follow-up patches. The order between init_completion() and complete() is deterministic, the Slave is marked as UNATTACHED either during a Master-initiated HardReset, or when the hardware detects the Slave no longer reports as ATTACHED. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> --- drivers/soundwire/bus.c | 20 ++++++++++++++++++++ drivers/soundwire/slave.c | 1 + 2 files changed, 21 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4980dfd6f3a3..a2267c3a1d2d 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -610,6 +610,26 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, enum sdw_slave_status status) { mutex_lock(&slave->bus->bus_lock); + + dev_vdbg(&slave->dev, + "%s: changing status slave %d status %d new status %d\n", + __func__, slave->dev_num, slave->status, status); + + if (status == SDW_SLAVE_UNATTACHED) { + dev_dbg(&slave->dev, + "%s: initializing completion for Slave %d\n", + __func__, slave->dev_num); + + init_completion(&slave->enumeration_complete); + + } else if ((status == SDW_SLAVE_ATTACHED) && + (slave->status == SDW_SLAVE_UNATTACHED)) { + dev_dbg(&slave->dev, + "%s: signaling completion for Slave %d\n", + __func__, slave->dev_num); + + complete(&slave->enumeration_complete); + } slave->status = status; mutex_unlock(&slave->bus->bus_lock); } diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index 08db0488e02d..e767a78066ee 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -46,6 +46,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->dev.of_node = of_node_get(to_of_node(fwnode)); slave->bus = bus; slave->status = SDW_SLAVE_UNATTACHED; + init_completion(&slave->enumeration_complete); slave->dev_num = 0; init_completion(&slave->probe_complete); slave->probed = false; -- 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:[~2020-01-15 0:09 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-15 0:08 [PATCH 00/10] soundwire: bus: fix race conditions, add suspend-resume Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 01/10] soundwire: bus: fix race condition with probe_complete signaling Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` Pierre-Louis Bossart [this message] 2020-01-15 0:08 ` [alsa-devel] [PATCH 02/10] soundwire: bus: fix race condition with enumeration_complete signaling Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 03/10] soundwire: bus: fix race condition with initialization_complete signaling Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 04/10] soundwire: bus: add PM/no-PM versions of read/write functions Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 05/10] soundwire: bus: write Slave Device Number without runtime_pm Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 06/10] soundwire: bus: add helper to clear Slave status to UNATTACHED Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 07/10] soundwire: bus: disable pm_runtime in sdw_slave_delete Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 08/10] soundwire: bus: fix io error when processing alert event Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 09/10] soundwire: bus: add clock stop helpers Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-01-15 0:08 ` [PATCH 10/10] soundwire: bus: don't treat CMD_IGNORED as error on ClockStop Pierre-Louis Bossart 2020-01-15 0:08 ` [alsa-devel] " Pierre-Louis Bossart 2020-02-10 14:30 ` [alsa-devel] [PATCH 00/10] soundwire: bus: fix race conditions, add suspend-resume Pierre-Louis Bossart 2020-02-10 14:30 ` Pierre-Louis Bossart 2020-02-25 10:27 ` Vinod Koul 2020-02-25 10:27 ` Vinod Koul 2020-02-25 15:23 ` Pierre-Louis Bossart
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