[PATCH] drm/amd/display: Use current connector state if NULL when checking bpc

[Harry Wentland]

On 2019-06-05 12:33 p.m., Nicholas Kazlauskas wrote:
> [Why]
> The old logic for checking which output depth to use relied on using
> the current connector state rather than the new proposed state. This
> was a problem when performing atomic commits since we weren't verifying
> it against the incoming max_requested_bpc.
> 
> But switching this to only use the new state and not the current state
> breaks filtering modes - it'll always assume that the maximum bpc
> supported by the display is in use, which will cause certain modes
> like 1440p at 144Hz to be filtered even when using 8bpc.
> 
> [How]
> Still use the connector->state if we aren't passed an explicit state.
> This will respect the max_bpc the user currently has when filtering
> modes.
> 
> Also remember to reset the default max_requested_bpc to 8 whenever
> connector reset is called to retain old behavior when using the new
> property.
> 
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Leo Li <sunpeng.li at amd.com>
> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index a698c8f272ed..f627c17a1039 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3046,6 +3046,9 @@ convert_color_depth_from_display_info(const struct drm_connector *connector,
>  {
>  	uint32_t bpc = connector->display_info.bpc;
>  
> +	if (!state)
> +		state = connector->state;
> +
>  	if (state) {
>  		bpc = state->max_bpc;
>  		/* Round down to the nearest even number. */
> @@ -3820,6 +3823,7 @@ void amdgpu_dm_connector_funcs_reset(struct drm_connector *connector)
>  		state->underscan_enable = false;
>  		state->underscan_hborder = 0;
>  		state->underscan_vborder = 0;
> +		state->base.max_requested_bpc = 8;
>  
>  		__drm_atomic_helper_connector_reset(connector, &state->base);
>  	}
>