Messages in this thread | | | Subject | Re: [alsa-devel] [PATCH 0/3] soundwire: use UniqueID only when relevant | From | Pierre-Louis Bossart <> | Date | Wed, 6 Nov 2019 13:30:27 -0600 |
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On 10/22/19 6:48 PM, Pierre-Louis Bossart wrote: > 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.
Vinod, this series has been submitted for review on October 22 and I answered to your questions. There's been no feedback since October 24, so is there any sustained objection here?
ACPI platforms are completely unmanageable without this patchset.
> > 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(-) >
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