[PATCH 4.19 109/175] drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christoph Niedermaier <cniedermaier at dh-electronics.com>

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.

Fixes: fe141cedc433 ("drm/imx: pd: Use bus format/flags provided by the bridge when available")
Signed-off-by: Christoph Niedermaier <cniedermaier at dh-electronics.com>
Cc: Marek Vasut <marex at denx.de>
Cc: Boris Brezillon <boris.brezillon at collabora.com>
Cc: Philipp Zabel <p.zabel at pengutronix.de>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: NXP Linux Team <linux-imx at nxp.com>
Cc: linux-arm-kernel at lists.infradead.org
To: dri-devel at lists.freedesktop.org
Tested-by: Max Krummenacher <max.krummenacher at toradex.com>
Acked-by: Boris Brezillon <boris.brezillon at collabora.com>
Signed-off-by: Marek Vasut <marex at denx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220201113643.4638-1-cniedermaier@dh-electronics.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/imx/parallel-display.c |    8 --------
 1 file changed, 8 deletions(-)

--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -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;