Patch "drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()" has been added to the 4.19-stable tree

This is a note to let you know that I've just added the patch titled

drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()

to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-imx-parallel-display-remove-bus-flags-check-in-imx_pd_bridge_atomic_check.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From 6061806a863e8b65b109eb06a280041cc7525442 Mon Sep 17 00:00:00 2001
From: Christoph Niedermaier <[email protected]>
Date: Tue, 1 Feb 2022 12:36:43 +0100
Subject: drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()

From: Christoph Niedermaier <[email protected]>

commit 6061806a863e8b65b109eb06a280041cc7525442 upstream.

If display timings were read from the devicetree using of_get_display_timing() and pixelclk-active is defined there, the flag DISPLAY_FLAGS_SYNC_POSEDGE/NEGEDGE is automatically generated. Through the function drm_bus_flags_from_videomode() e.g. called in the panel-simple driver this flag got into the bus flags, but then in imx_pd_bridge_atomic_check() the bus flag check failed and will not initialize the display. The original commit fe141cedc433 does not explain why this check was introduced. So remove the bus flags check, because it stops the initialization of the display with valid bus flags.

To: [email protected]

---
 drivers/gpu/drm/imx/parallel-display.c |    8 --------
 1 file changed, 8 deletions(-)

@@ -235,14 +235,6 @@ static int imx_pd_bridge_atomic_check(st
 	if (!imx_pd_format_supported(bus_fmt))
 		return -EINVAL;
 
-	if (bus_flags &
-	    ~(DRM_BUS_FLAG_DE_LOW | DRM_BUS_FLAG_DE_HIGH |
-	      DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE |
-	      DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)) {
-		dev_warn(imxpd->dev, "invalid bus_flags (%x)\n", bus_flags);
-		return -EINVAL;
-	}
-
 	bridge_state->output_bus_cfg.flags = bus_flags;
 	bridge_state->input_bus_cfg.flags = bus_flags;
 	imx_crtc_state->bus_flags = bus_flags;

Patches currently in stable-queue which might be from [email protected] are

queue-4.19/drm-imx-parallel-display-remove-bus-flags-check-in-imx_pd_bridge_atomic_check.patch