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> Subject: [PATCH 0/3] soundwire: use UniqueID only when relevant Date: Tue, 22 Oct 2019 18:48:05 -0500 [thread overview] Message-ID: <20191022234808.17432-1-pierre-louis.bossart@linux.intel.com> (raw) The hardware UniqueID, typically enabled with pin-strapping, is required during enumeration to avoid conflicts between devices of the same type. When there are no devices of the same type, using the UniqueID is overkill and results in a lot of probe errors due to mismatches between ACPI tables and hardware capabilities. For example it's not uncommon for BIOS vendors to copy/paste the same settings between platforms but the hardware pin-strapping is different. This is perfectly legit and permitted by MIPI specs. With this patchset, the UniqueID is only used when multiple devices of the same type are detected. The loop to detect multiple identical devices is not super efficient but with typically fewer than 4 devices per link there's no real incentive to be smarter. This change is only implemented for ACPI platforms, for DeviceTree there is no change. Pierre-Louis Bossart (3): soundwire: remove bitfield for unique_id, use u8 soundwire: slave: add helper to extract slave ID soundwire: ignore uniqueID when irrelevant drivers/soundwire/bus.c | 7 +-- drivers/soundwire/slave.c | 98 +++++++++++++++++++++++++++-------- include/linux/soundwire/sdw.h | 4 +- 3 files changed, 84 insertions(+), 25 deletions(-) -- 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, Bard liao <yung-chuan.liao@linux.intel.com>, Rander Wang <rander.wang@linux.intel.com> Subject: [alsa-devel] [PATCH 0/3] soundwire: use UniqueID only when relevant Date: Tue, 22 Oct 2019 18:48:05 -0500 [thread overview] Message-ID: <20191022234808.17432-1-pierre-louis.bossart@linux.intel.com> (raw) The hardware UniqueID, typically enabled with pin-strapping, is required during enumeration to avoid conflicts between devices of the same type. When there are no devices of the same type, using the UniqueID is overkill and results in a lot of probe errors due to mismatches between ACPI tables and hardware capabilities. For example it's not uncommon for BIOS vendors to copy/paste the same settings between platforms but the hardware pin-strapping is different. This is perfectly legit and permitted by MIPI specs. With this patchset, the UniqueID is only used when multiple devices of the same type are detected. The loop to detect multiple identical devices is not super efficient but with typically fewer than 4 devices per link there's no real incentive to be smarter. This change is only implemented for ACPI platforms, for DeviceTree there is no change. Pierre-Louis Bossart (3): soundwire: remove bitfield for unique_id, use u8 soundwire: slave: add helper to extract slave ID soundwire: ignore uniqueID when irrelevant drivers/soundwire/bus.c | 7 +-- drivers/soundwire/slave.c | 98 +++++++++++++++++++++++++++-------- include/linux/soundwire/sdw.h | 4 +- 3 files changed, 84 insertions(+), 25 deletions(-) -- 2.20.1 _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
next reply other threads:[~2019-10-22 23:48 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-22 23:48 Pierre-Louis Bossart [this message] 2019-10-22 23:48 ` [alsa-devel] [PATCH 0/3] soundwire: use UniqueID only when relevant Pierre-Louis Bossart 2019-10-22 23:48 ` [PATCH 1/3] soundwire: remove bitfield for unique_id, use u8 Pierre-Louis Bossart 2019-10-22 23:48 ` [alsa-devel] " Pierre-Louis Bossart 2019-10-24 11:29 ` Vinod Koul 2019-10-24 11:29 ` [alsa-devel] " Vinod Koul 2019-10-24 12:42 ` Pierre-Louis Bossart 2019-10-24 12:42 ` Pierre-Louis Bossart 2019-10-22 23:48 ` [PATCH 2/3] soundwire: slave: add helper to extract slave ID Pierre-Louis Bossart 2019-10-22 23:48 ` [alsa-devel] " Pierre-Louis Bossart 2019-10-22 23:48 ` [PATCH 3/3] soundwire: ignore uniqueID when irrelevant Pierre-Louis Bossart 2019-10-22 23:48 ` [alsa-devel] " Pierre-Louis Bossart 2019-10-24 11:39 ` Vinod Koul 2019-10-24 11:39 ` [alsa-devel] " Vinod Koul 2019-10-24 12:59 ` Pierre-Louis Bossart 2019-10-24 12:59 ` Pierre-Louis Bossart 2019-11-06 19:30 ` [alsa-devel] [PATCH 0/3] soundwire: use UniqueID only when relevant Pierre-Louis Bossart 2019-11-06 19:30 ` Pierre-Louis Bossart 2019-11-09 11:18 ` Vinod Koul 2019-11-09 11:18 ` [alsa-devel] " Vinod Koul
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=20191022234808.17432-1-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=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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.