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

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

[Christoph Niedermaier]

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@dh-electronics.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
To: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/imx/parallel-display.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c
index a8aba0141ce7..06cb1a59b9bc 100644
--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -217,14 +217,6 @@ static int imx_pd_bridge_atomic_check(struct drm_bridge *bridge,
 	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;
-- 
2.11.0


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

[Marek Vasut]

On 2/1/22 12:03, Christoph Niedermaier wrote:
> 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@dh-electronics.com>
> Cc: Marek Vasut <marex@denx.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: NXP Linux Team <linux-imx@nxp.com>
> Cc: linux-arm-kernel@lists.infradead.org
> To: dri-devel@lists.freedesktop.org
> ---
>   drivers/gpu/drm/imx/parallel-display.c | 8 --------
>   1 file changed, 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c
> index a8aba0141ce7..06cb1a59b9bc 100644
> --- a/drivers/gpu/drm/imx/parallel-display.c
> +++ b/drivers/gpu/drm/imx/parallel-display.c
> @@ -217,14 +217,6 @@ static int imx_pd_bridge_atomic_check(struct drm_bridge *bridge,
>   	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;
> -	}

+CC Boris

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