Re: [PATCH 1/4] drm: xlnx: zynqmp_dpsub: Make drm bridge

Hi Tomi,

Thanks for your response. 

Date: Wed, 17 Jan 2024 16:06:31 +0200
From: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
To: Anatoliy Klymenko <redacted>,
        laurent.pinchart@ideasonboard.com, maarten.lankhorst@linux.intel.com,
        mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com,
        daniel@ffwll.ch, michal.simek@amd.com,
        dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] drm: xlnx: zynqmp_dpsub: Make drm bridge
        discoverable
Message-ID: [ref]
Content-Type: text/plain; charset=UTF-8; format=flowed

On 13/01/2024 01:42, Anatoliy Klymenko wrote:

quoted

Assign device of node to bridge prior registering it. This will make
said bridge discoverable by separate crtc driver.

I think a few words on why this is needed (and why it wasn't needed
before) would be nice.

Sure. I will update. 
"  ZynqMP DPSUB supports 2 input modes: DMA based and live video.

    In the first mode, the driver implements CRTC and DP encoder DRM bridge to
    model the complete display pipeline. In this case, DRM bridge is being directly
    instantiated within the driver, not using any bridge discovery mechanisms.

    In the live video input mode video signal is generated by FPGA fabric and passed
    into DPSUB over the connected bus. In this mode driver exposes the DP encoder as
    a DRM bridge, expecting external CRTC to discover it via
    drm_of_find_panel_or_bridge() or a similar call. This discovery relies on
    drm_bridge.of_node being properly set.

    Assign device OF node to the bridge prior to registering it. This will
    make said bridge discoverable by an external CRTC driver.".
How does this sound?

Other than that:

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

  Tomi

quoted

Signed-off-by: Anatoliy Klymenko <redacted>
---
  drivers/gpu/drm/xlnx/zynqmp_dp.c | 1 +
  1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c

b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index a0606fab0e22..d60b7431603f 100644

--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c

@@ -1721,6 +1721,7 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
      bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
                  | DRM_BRIDGE_OP_HPD;
      bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
+     bridge->of_node = dp->dev->of_node;
      dpsub->bridge = bridge;

      /*

Regards
Anatoliy

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