Re: [PATCH v5 2/2] drm/bridge: lvds-codec: Add support for pixel data sampling edge select

On 10/17/21 7:40 PM, Sam Ravnborg wrote:

Hi Marek,

On Sun, Oct 17, 2021 at 07:29:51PM +0200, Marek Vasut wrote:

quoted

On 10/17/21 6:49 PM, Sam Ravnborg wrote:

[...]

quoted

quoted

+	/*
+	 * Encoder might sample data on different clock edge than the display,
+	 * for example OnSemi FIN3385 has a dedicated strapping pin to select
+	 * the sampling edge.
+	 */
+	if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
+	    !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
+		lvds_codec->timings.input_bus_flags = val ?
+			DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
+			DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+	}
+
   	/*
   	 * The panel_bridge bridge is attached to the panel's of_node,
   	 * but we need a bridge attached to our of_node for our user
   	 * to look up.
   	 */
   	lvds_codec->bridge.of_node = dev->of_node;
+	lvds_codec->bridge.timings = &lvds_codec->timings;

I do not understand how this will work. The only field that is set is timings.input_bus_flags
but any user will see bridge.timings is set and will think this is all
timing info.

Maybe I just misses something obvious?

Is there anything else in those timings that should be set ? See
include/drm/drm_bridge.h around line 640

setup_time_ps/hold_time_ps/dual_link isn't supported by this driver, so it
is 0 or false anyway, i.e. no change.

Just me being confused with display_timings. Patch looks good.
Reviewed-by: Sam Ravnborg <redacted>

Ping me in a few days to apply it if there is no more feedback.

ACK