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

From: Marek Vasut <marex@denx.de>
To: Christoph Niedermaier <cniedermaier@dh-electronics.com>,
	dri-devel@lists.freedesktop.org,
	Boris Brezillon <bbrezillon@kernel.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()
Date: Tue, 1 Feb 2022 12:10:21 +0100	[thread overview]
Message-ID: <4f7d2ec6-cde9-4adf-141d-4e4651371bae@denx.de> (raw)
In-Reply-To: <20220201110358.3530-1-cniedermaier@dh-electronics.com>

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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