[PATCH] drm/xe: Eliminate usage of TIMESTAMP_OVERRIDE

[Lucas De Marchi]

On Tue, Feb 25, 2025 at 02:49:09PM -0800, Matt Roper wrote:
>Recent discussions with the hardware architects have revealed that
>the TIMESTAMP_OVERRIDE register is never expected to hold a valid/useful
>value on production hardware.  That register would only get used by
>hardware workarounds (although there are none that use it today) or
>during early internal hardware testing.
>
>Due to lack of documentation it's not clear exactly what the driver
>should be doing if CTC_MODE[0] is set (or even whether that's a setting
>that would ever be encountered on real hardware), but it's definitely
>not what Xe and i915 have been doing.  So drop the incorrect code trying
>to use TIMESTAMP_REGISTER.  If the driver does encounter CTC_MODE[0] in
>the wild, we'll print a warning and just continue trying to use the
>crystal clock frequency since that's probably less incorrect than what
>we're doing today.
>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
>Signed-off-by: Matt Roper <matthew.d.roper at intel.com>


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

thanks
Lucas De Marchi