Hello,
> The tc358768 declares static bridge timings requiring pixel data to be
> sampled on the positive clock edge.
>
> However, the DRM core default propagation simply copies the output-side
> bus flags, coming from the next bridge, connector or panel, to the
> input side. If the propagated flags are incompatible with the bridge
> ones, the data is wrongly sampled, typically resulting in visual
> artifacts on the panel.
>
> Implement the atomic_check hook, replacing the mutually exclusive
> mode_fixup, and set the bridge state input bus flags to the ones
> required by the tc358768. The sync polarity defaulting previously done
> in mode_fixup is carried over into atomic_check unchanged.
>
> Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver")
> Cc: [email protected]
> Signed-off-by: Leonardo Costa <[email protected]>
> ---
> drivers/gpu/drm/bridge/tc358768.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358768.c
> b/drivers/gpu/drm/bridge/tc358768.c
> index 0d85120fcc7a3..0516a331e71ba 100644
> --- a/drivers/gpu/drm/bridge/tc358768.c
> +++ b/drivers/gpu/drm/bridge/tc358768.c
> @@ -1262,10 +1262,13 @@ tc358768_atomic_get_input_bus_fmts(struct drm_bridge
> *bridge,
> return input_fmts;
> }
>
> -static bool tc358768_mode_fixup(struct drm_bridge *bridge,
> - const struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode)
> +static int tc358768_bridge_atomic_check(struct drm_bridge *bridge,
> + struct drm_bridge_state *bridge_state,
> + struct drm_crtc_state *crtc_state,
> + struct drm_connector_state *conn_state)
> {
> + struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
> +
> /* Default to positive sync */
>
> if (!(adjusted_mode->flags &
> @@ -1276,13 +1279,15 @@ static bool tc358768_mode_fixup(struct drm_bridge
> *bridge,
> (DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC)))
> adjusted_mode->flags |= DRM_MODE_FLAG_PVSYNC;
>
> - return true;
> + bridge_state->input_bus_cfg.flags = bridge->timings->input_bus_flags;
> +
> + return 0;
> }
>
> static const struct drm_bridge_funcs tc358768_bridge_funcs = {
> .attach = tc358768_bridge_attach,
> .mode_valid = tc358768_bridge_mode_valid,
> - .mode_fixup = tc358768_mode_fixup,
> + .atomic_check = tc358768_bridge_atomic_check,
> .atomic_pre_enable = tc358768_bridge_atomic_pre_enable,
> .atomic_enable = tc358768_bridge_atomic_enable,
> .atomic_disable = tc358768_bridge_atomic_disable,
Please ignore this, as it was not meant to be sent in reply to the thread
above. That was an accident.
