linux-kernel - Re: [PATCH 16/17] [NOT-FOR-MERGE] media: atomsip: pci: add DMI match for Microsoft Surface 3 with broken DMI (OEMB)

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Message-ID: <71b5b886-2ca1-27a9-6776-b3bcc430e5ed@redhat.com>
Date:   Mon, 18 Oct 2021 09:56:45 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Tsuchiya Yuto <kitakar@...il.com>
Cc:     Patrik Gfeller <patrik.gfeller@...il.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Aniket Bhattacharyea <aniketmail669@...il.com>,
        Aline Santana Cordeiro <alinesantanacordeiro@...il.com>,
        Yang Yingliang <yangyingliang@...wei.com>,
        Hans Verkuil <hverkuil-cisco@...all.nl>,
        Alan <alan@...ux.intel.com>,
        Dinghao Liu <dinghao.liu@....edu.cn>,
        linux-media@...r.kernel.org, linux-staging@...ts.linux.dev,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 16/17] [NOT-FOR-MERGE] media: atomsip: pci: add DMI match
 for Microsoft Surface 3 with broken DMI (OEMB)

Hi,

On 10/17/21 18:19, Tsuchiya Yuto wrote:
> This commit is added for Surface 3 with broken DMI table. HACK-ish.
> Not intended for upstreaming. Thus, NOT-FOR-MERGE. But, if someone
> knows a nicer way to address this, comments are welcome...
> 
>> 8-----------------------------------------------------------------8<
> 
> On some Microsoft Surface 3, the DMI table gets corrupted for unknown
> reasons and breaks existing DMI matching used for device-specific quirks.
> 
> This commit adds the (broken) DMI data into dmi_system_id tables used
> for quirks so that the driver can enable quirks even on the affected
> systems.
> 
> On affected systems, the DMI data will look like this:
> 
>         $ grep . /sys/devices/virtual/dmi/id/{bios_vendor,board_name,board_vendor,\
>         chassis_vendor,product_name,sys_vendor}
>         /sys/devices/virtual/dmi/id/bios_vendor:American Megatrends Inc.
>         /sys/devices/virtual/dmi/id/board_name:OEMB
>         /sys/devices/virtual/dmi/id/board_vendor:OEMB
>         /sys/devices/virtual/dmi/id/chassis_vendor:OEMB
>         /sys/devices/virtual/dmi/id/product_name:OEMB
>         /sys/devices/virtual/dmi/id/sys_vendor:OEMB

I wonder what the bios_date field contains ? Typically when the DMI strings
are no good (e.g. often they contain "Default String" or "To be filled by OEM")
we add a check on the bios-date, which together with the broken strings is
considered unique enough to still allow a match with broken strings in the
kernel.

Also have you tried doing something like "load bios/setup defaults" in
the BIOS setup ? Maybe that helps ?

Regards,

Hans





> 
> Expected:
> 
>         $ grep . /sys/devices/virtual/dmi/id/{bios_vendor,board_name,board_vendor,\
>         chassis_vendor,product_name,sys_vendor}
>         /sys/devices/virtual/dmi/id/bios_vendor:American Megatrends Inc.
>         /sys/devices/virtual/dmi/id/board_name:Surface 3
>         /sys/devices/virtual/dmi/id/board_vendor:Microsoft Corporation
>         /sys/devices/virtual/dmi/id/chassis_vendor:Microsoft Corporation
>         /sys/devices/virtual/dmi/id/product_name:Surface 3
>         /sys/devices/virtual/dmi/id/sys_vendor:Microsoft Corporation
> 
> Signed-off-by: Tsuchiya Yuto <kitakar@...il.com>
> ---
>  .../staging/media/atomisp/pci/atomisp_gmin_platform.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> index 948eb6f809f5..3868d64cbc2b 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> @@ -377,6 +377,17 @@ static const struct dmi_system_id gmin_vars[] = {
>  		},
>  		.driver_data = surface3_vars,
>  	},
> +	{
> +		.ident = "Surface 3",
> +		.matches = {
> +			/* DMI data for Surface 3 with broken DMI table */
> +			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
> +			DMI_MATCH(DMI_BOARD_NAME, "OEMB"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "OEMB"),
> +			DMI_MATCH(DMI_SYS_VENDOR, "OEMB"),
> +		},
> +		.driver_data = surface3_vars,
> +	},
>  	{}
>  };
>  
>