On Mon, 18 May 2026, "Kandpal, Suraj" <[email protected]> wrote:
>> Subject: [PATCH v3 03/31] drm/i915/bios: log unsupported VS/PE-O parsing
>>
>> Search for VBT #57. Check for failure since pre-ICL GOPs do not contain the
>> block. Check also if VBT version is appropriately up-to-date.
>>
>> Issue a debug message when port requests to override VS/PE and parsing VBT
>> #57 for the platform has not yet been implemented.
>>
>> Signed-off-by: Michał Grzelak <[email protected]>
>> ---
>> drivers/gpu/drm/i915/display/intel_bios.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
>> b/drivers/gpu/drm/i915/display/intel_bios.c
>> index 5700de438fdfd..3f9e4d31c7375 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -2185,6 +2185,23 @@ parse_compression_parameters(struct intel_display
>> *display)
>> }
>> }
>>
>> +static void
>> +parse_vswing_preemph_override(struct intel_display *display) {
>> + const struct bdb_vswing_preemph *block;
>> +
>> + if (display->vbt.version < 218)
>> + return;
>> +
>> + block = bdb_find_section(display, BDB_VSWING_PREEMPH);
>> +
>> + /* pre-ICL GOP don't have VBT #57 */
>
> If we already know pre ICL does have VBT #57 for sure why even try the find
> section for check vbt versions lets just return early after display_ver()
> check , which is done even before the vbt.version check .
Please don't add unnecessary platform or display version checks in
intel_bios.c.
BR,
Jani.
>
> Regards,
> Suraj Kandpal
>
>> + if (!block)
>> + return;
>> +
>> + drm_dbg_kms(display->drm, "VS/PE-O parsing not yet supported\n"); }
>> +
>> static u8 translate_iboost(struct intel_display *display, u8 val) {
>> static const u8 mapping[] = { 1, 3, 7 }; /* See VBT spec */ @@ -3276,6
>> +3293,7 @@ void intel_bios_init(struct intel_display *display)
>>
>> /* Depends on child device list */
>> parse_compression_parameters(display);
>> + parse_vswing_preemph_override(display);
>>
>> out:
>> if (!vbt) {
>> --
>> 2.45.2
>
--
Jani Nikula, Intel
