On Mon, Sep 07, 2026 at 11:56:01AM +0300, Tomi Valkeinen wrote:
> On 03/07/2026 00:24, Laurent Pinchart wrote:
> > On Mon, Jun 15, 2026 at 04:11:57PM +0300, Tomi Valkeinen wrote:
> >> Enabling DSI clocks on rcar-du needs some tricks as the DU dot clock is
> >> provided by the DSI. Thus, we call rcar_mipi_dsi_pclk_enable() from the
> >> crtc, when enabling the crtc.
> >>
> >> With DSC (added in upcoming patch) in the pipeline, between the DU and
> >> the DSI, the above call path is broken as the crtc tries to call
> >> rcar_mipi_dsi_pclk_enable() on the DSC.
> >>
> >> To solve this problem, make sure we store the DSI bridge to the
> >> rcdu->dsi[] array, instead of the first bridge in the DSI pipeline
> >> (which can be DCS), by checking the bridge's bridge->type.
> >>
> >> Signed-off-by: Tomi Valkeinen <[email protected]>
> >> ---
> >>   drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c | 18 ++++++++++++++++--
> >>   drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c   |  1 +
> >>   2 files changed, 17 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c 
> >> b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
> >> index db2088529b48..ac85838ab3b8 100644
> >> --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
> >> +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
> >> @@ -89,9 +89,23 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
> >>                            drm_bridge_get(bridge);
> >>   
> >>            if (output == RCAR_DU_OUTPUT_DSI0 ||
> >> -              output == RCAR_DU_OUTPUT_DSI1)
> >> +              output == RCAR_DU_OUTPUT_DSI1) {
> >> +                  struct drm_bridge *dsi_bridge;
> >> +
> >> +                  /*
> >> +                   * When we have a DSC block between the DU and the DSI,
> >> +                   * the "bridge" points to the DSC. Detect the DSC by 
> >> looking
> >> +                   * at the bridge type, and skip the DSC if the bridge 
> >> is not
> >> +                   * the DSI bridge.
> >> +                   */
> >> +
> >> +                  dsi_bridge = bridge->type == DRM_MODE_CONNECTOR_DSI ?
> >> +                                               bridge :
> >> +                                               bridge->next_bridge;
> > 
> > The indentation looks weird.
> > 
> >                     dsi_bridge = bridge->type == DRM_MODE_CONNECTOR_DSI
> >                                ? bridge : bridge->next_bridge;
> 
> That looks even weirder, you are associating = and ? there. What about:
> 
> dsi_bridge = bridge->type == DRM_MODE_CONNECTOR_DSI ?
>            bridge : bridge->next_bridge;

I like my version better :-)

-- 
Regards,

Laurent Pinchart

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