On Tue, 17 Dec 2024, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
> On Tue, 17 Dec 2024, Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> wrote:
>> Check for DSC support before computing link config with DSC.
>> For DP MST we are already doing the same.
>>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
>> Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
>> ---
>> drivers/gpu/drm/i915/display/intel_dp.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 908b9887f89b..dd2da9facaad 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -2375,9 +2375,6 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>> intel_dp_supports_fec(intel_dp, connector, pipe_config) &&
>> !intel_dp_is_uhbr(pipe_config));
>>
>> - if (!intel_dp_supports_dsc(intel_dp, connector, pipe_config))
>> - return -EINVAL;
>> -
>> if (!intel_dp_dsc_supports_format(connector, pipe_config->output_format))
>> return -EINVAL;
>>
>> @@ -2652,6 +2649,9 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>> str_yes_no(ret), str_yes_no(joiner_needs_dsc),
>> str_yes_no(intel_dp->force_dsc_en));
>>
>> + if (!intel_dp_supports_dsc(intel_dp, connector, pipe_config))
>> + return -EINVAL;
>> +
>
> The (pre-existing) problem with this is that we debug log we fall back
> to DSC, while we don't.
>
> Maybe we should do something like this instead, both in SST and MST code:
On second thought, this can also come as a follow-up later. I don't want
to block the series with this.
BR,
Jani.
>
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2644,6 +2644,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> dsc_needed = true;
> }
>
> + if (dsc_needed && !intel_dp_supports_dsc(connector, pipe_config)) {
> + drm_dbg_kms(display->drm, "DSC required but not available.\n");
> + return -EINVAL;
> + }
> +
> if (dsc_needed) {
> drm_dbg_kms(display->drm,
> "Try DSC (fallback=%s, joiner=%s, force=%s)\n",
>
> BR,
> Jani.
>
>> if (!intel_dp_compute_config_limits(intel_dp, pipe_config,
>> respect_downstream_limits,
>> true,
--
Jani Nikula, Intel
