Re: [PATCH v2] i2c: i2c-scmi: add a MS HID

[Wolfram Sang <wsa@the-dreams.de>]

[-- Attachment #1: Type: text/plain, Size: 1622 bytes --]

On Tue, Apr 04, 2017 at 07:18:27PM +0300, Viktor Krasnov wrote:
> From: Edgar Cherkasov <echerkasov@dev.rtsoft.ru>
> 
> Description of the problem:
>  - i2c-scmi driver contains only two identifiers "SMBUS01" and "SMBUSIBM";
>  - the fist HID (SMBUS01) is clearly defined in "SMBus Control Method
>    Interface Specification, version 1.0": "Each device must specify
>    'SMBUS01' as its _HID and use a unique _UID value";
>  - unfortunately, BIOS vendors (like AMI) seem to ignore this requirement
>    and implement "SMB0001" HID instead of "SMBUS01";
>  - I speculate that they do this because only "SMB0001" is hard coded in
>    Windows SMBus driver produced by Microsoft.
> 
> This leads to following situation:
>  - SMBus works out of box in Windows but not in Linux;
>  - board vendors are forced to add correct "SMBUS01" HID to BIOS to make
>    SMBus work in Linux. Moreover the same board vendors complain that
>    tools (3-rd party ASL compiler) do not like the "SMBUS01" identifier
>    and produce errors.  So they need to constantly patch the compiler for
>    each new version of BIOS.
> 
> As it is very unlikely that BIOS vendors implement a correct HID in
> future, I would propose to consider whether it is possible to work around
> the problem by adding MS HID to the Linux i2c-scmi driver.
> 
> v2: move the definition of the new HID to the driver itself.
> 
> Signed-off-by: Edgar Cherkasov <echerkasov@dev.rtsoft.ru>
> Signed-off-by: Michael Brunner <Michael.Brunner@kontron.com>
> Acked-by: Viktor Krasnov <vkrasnov@dev.rtsoft.ru>

Applied to for-next, thanks!


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]