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 12/22] soundwire: bus: fix race condition with enumeration_complete signaling
Date: Thu, 14 Nov 2019 12:16:52 -0600 [thread overview]
Message-ID: <20191114181702.22254-13-pierre-louis.bossart@linux.intel.com> (raw)
In-Reply-To: <20191114181702.22254-1-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 | 19 +++++++++++++++++++
drivers/soundwire/slave.c | 1 +
2 files changed, 20 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 9f03a915a09a..e34b5ed534b3 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -637,6 +637,25 @@ 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) {
+ 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 15ac89ecae01..76fdfbd8b50d 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -52,6 +52,7 @@ static int sdw_slave_add(struct sdw_bus *bus,
slave->dev.type = &sdw_slave_type;
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:[~2019-11-14 18:26 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 18:16 [alsa-devel] [PATCH v3 00/22] soundwire: code hardening and suspend-resume support Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 01/22] soundwire: intel/cadence: fix timeouts in MSI mode Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 02/22] soundwire: bus: fix race condition with probe_complete signaling Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [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] [PATCH v3 04/22] soundwire: bus: write Slave Device Number without runtime_pm Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [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] [PATCH v3 06/22] soundwire: intel: Add basic power management support Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 07/22] soundwire: intel: add pm_runtime support Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 08/22] soundwire: intel: reset pm_runtime status during system resume Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 09/22] soundwire: bus: add helper to reset Slave status to UNATTACHED Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 10/22] soundwire: intel: call helper to reset Slave states on resume Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 11/22] soundwire: bus: check first if Slaves become UNATTACHED Pierre-Louis Bossart
2019-11-14 18:16 ` Pierre-Louis Bossart [this message]
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 13/22] soundwire: bus: fix race condition with initialization_complete signaling Pierre-Louis Bossart
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 ` [alsa-devel] [PATCH v3 15/22] soundwire: intel: disable pm_runtime when removing a master Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 16/22] soundwire: bus: disable pm_runtime in sdw_slave_delete Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 17/22] soundwire: stream: remove redundant pr_err traces Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 18/22] soundwire: stream: update state machine and add state checks Pierre-Louis Bossart
2019-11-14 18:16 ` [alsa-devel] [PATCH v3 19/22] soundwire: stream: only prepare stream when it is configured Pierre-Louis Bossart
2019-11-14 18:17 ` [alsa-devel] [PATCH v3 20/22] soundwire: stream: do not update parameters during DISABLED-PREPARED transition Pierre-Louis Bossart
2019-11-14 18:17 ` [alsa-devel] [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] [PATCH v3 22/22] soundwire: intel: pm_runtime idle scheduling Pierre-Louis Bossart
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191114181702.22254-13-pierre-louis.bossart@linux.intel.com \
--to=pierre-louis.bossart@linux.intel.com \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jank@cadence.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rander.wang@linux.intel.com \
--cc=ranjani.sridharan@linux.intel.com \
--cc=sanyog.r.kale@intel.com \
--cc=slawomir.blauciak@intel.com \
--cc=srinivas.kandagatla@linaro.org \
--cc=tiwai@suse.de \
--cc=vkoul@kernel.org \
--cc=yung-chuan.liao@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).