From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mika Westerberg Subject: Re: [PATCH v2] i2c: i2c-scmi: add a MS HID Date: Thu, 6 Apr 2017 11:03:09 +0300 Message-ID: <20170406080309.GP2957@lahna.fi.intel.com> References: <1491322707-2991-1-git-send-email-vkrasnov@dev.rtsoft.ru> <20170405145932.3ef689d5@endymion> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170405145932.3ef689d5@endymion> Sender: linux-acpi-owner@vger.kernel.org To: Jean Delvare Cc: Viktor Krasnov , wsa@the-dreams.de, linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org, andriy.shevchenko@linux.intel.com, jarkko.nikula@linux.intel.com, echerkasov@dev.rtsoft.ru, Michael.Brunner@kontron.com List-Id: linux-i2c@vger.kernel.org On Wed, Apr 05, 2017 at 02:59:32PM +0200, Jean Delvare wrote: > On Tue, 4 Apr 2017 19:18:27 +0300, Viktor Krasnov wrote: > > From: Edgar Cherkasov > > > > 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 > > Signed-off-by: Michael Brunner > > Acked-by: Viktor Krasnov > > Reviewed-by: Jean Delvare Reviewed-by: Mika Westerberg