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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Jacob Bazata <jacobbazata@gmail.com>,
	wsa+renesas@sang-engineering.com, westeri@kernel.org,
	linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: acpi: Add VEN_04F3 to i2c_acpi_force_100khz_device_ids
Date: Tue, 19 May 2026 14:08:29 +0300	[thread overview]
Message-ID: <agxErb9VB_T7SLCA@ashevche-desk.local> (raw)
In-Reply-To: <20260519100529.GA8580@black.igk.intel.com>

On Tue, May 19, 2026 at 12:05:29PM +0200, Mika Westerberg wrote:
> On Tue, May 19, 2026 at 01:24:24AM -0400, Jacob Bazata wrote:
> > This model trackpad (04F3:32AA), found on various Dell XPS models
> > from 2023 including XPS 9500, 9510, 9520 and 9530 is well documented to,
> > at random, exhibit excessive smoothing with no obvious cause, similar
> > to other trackpad devices listed in the i2c_acpi_force_100khz_device
> > _ids struct.
> > 
> > Forcing the bus to 100KHz eliminates this behavior.

...

> > +	{ "VEN_04F3", 0 },
> 
> This is interesting ACPI ID. Adding Andy just in case he has any comments
> on it.

Yes, it's simply bogus and not following the ACPI specification [0]. We might
add the bogus IDs, but that has to be justified in the commit message:

- Is the device available on a wild market?
- If no, drop the patch, fix the firmware (I'm here to help with ACPI process bits)
- If yes, provide the Device name, model, year, et cetera to unique distinguish it,
  provide an excerpt from DSDT to show how this device is described there
- Also browse the MS catalog [1], duckduckgo, google for the ID to see if it
appears in some respectful sources
- Additionally, try to submit a bug report to the vendor of the device to point
out that this is bogus ID and must be fixed  (in a new BIOSes)

The more information you find and provide the better. (But distinguish the
important from secondary info,)

[0]: https://uefi.org/specs/ACPI/6.6/06_Device_Configuration.html#hid-hardware-id
[1]: https://www.catalog.update.microsoft.com/Search.aspx?q=ven_04f3

-- 
With Best Regards,
Andy Shevchenko



  reply	other threads:[~2026-05-19 11:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-19  5:24 [PATCH] i2c: acpi: Add VEN_04F3 to i2c_acpi_force_100khz_device_ids Jacob Bazata
2026-05-19 10:05 ` Mika Westerberg
2026-05-19 11:08   ` Andy Shevchenko [this message]
  -- strict thread matches above, loose matches on Subject: below --
2026-05-19  5:10 Jacob Bazata

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