From mboxrd@z Thu Jan  1 00:00:00 1970
From: p.zabel@pengutronix.de (Philipp Zabel)
Date: Thu, 10 Apr 2014 10:55:51 +0200
Subject: [PATCH] staging: imx-drm-core: skip components whose parent
 device is disabled
In-Reply-To: <1397112193-15817-1-git-send-email-shawn.guo@freescale.com>
References: <1397112193-15817-1-git-send-email-shawn.guo@freescale.com>
Message-ID: <1397120151.3226.11.camel@paszta.hi.pengutronix.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Am Donnerstag, den 10.04.2014, 14:43 +0800 schrieb Shawn Guo:
> In a board setup which disables LDB device node completely by changing
> status to 'disabled', and only enables HDMI device, we're running into
> the problem that imx-drm master never succeeds in binding, and hence
> HDMI does not come up either.
> 
> &ldb {
> 	status = "disabled";
> 
> 	lvds-channel at 1 {
> 		...
> 		status = "okay";
> 	};
> };

I'd say this is a misconfiguration. Should we add a warning for this
case?

> The imx-drm-core should really skip the LVDS channels no matter what
> lvds-channel's status is, if LDB device is disabled.  So let's give one
> more check on parent device availability before add the component.
> 
> Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
> ---
>  drivers/staging/imx-drm/imx-drm-core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
> index 4144a75..e494ef9 100644
> --- a/drivers/staging/imx-drm/imx-drm-core.c
> +++ b/drivers/staging/imx-drm/imx-drm-core.c
> @@ -672,7 +672,8 @@ static int imx_drm_platform_probe(struct platform_device *pdev)
>  
>  		for_each_child_of_node(port, ep) {
>  			remote = of_graph_get_remote_port_parent(ep);
> -			if (!remote || !of_device_is_available(remote)) {
> +			if (!remote || !of_device_is_available(remote) ||
> +			    !of_device_is_available(remote->parent)) {
>  				of_node_put(remote);
>  				continue;
>  			}

regards
Philipp