linux-kernel - Re: [PATCH 2/7] drm/meson: remove useless recursive components matching

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <56fe9cd4-6903-b1d3-d2bd-8b559fdd4304@baylibre.com>
Date:   Fri, 15 Oct 2021 09:53:30 +0200
From:   Neil Armstrong <narmstrong@...libre.com>
To:     Sam Ravnborg <sam@...nborg.org>
Cc:     daniel@...ll.ch, Laurent.pinchart@...asonboard.com,
        martin.blumenstingl@...glemail.com,
        dri-devel@...ts.freedesktop.org, linux-amlogic@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/7] drm/meson: remove useless recursive components
 matching

Hi Sam,

On 14/10/2021 19:49, Sam Ravnborg wrote:
> Hi Neil,
> 
> one comment below. Other than that
> Acked-by: Sam Ravnborg <sam@...nborg.org>
> 
> 	Sam
> 
> On Thu, Oct 14, 2021 at 05:26:01PM +0200, Neil Armstrong wrote:
>> The initial design was recursive to cover all port/endpoints, but only the first layer
>> of endpoints should be covered by the components list.
>> This also breaks the MIPI-DSI init/bridge attach sequence, thus only parse the
>> first endpoints instead of recursing.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@...libre.com>
>> ---
>>  drivers/gpu/drm/meson/meson_drv.c | 62 +++++++++++--------------------
>>  1 file changed, 21 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
>> index bc0d60df04ae..b53606d8825f 100644
>> --- a/drivers/gpu/drm/meson/meson_drv.c
>> +++ b/drivers/gpu/drm/meson/meson_drv.c
>> @@ -427,46 +427,6 @@ static int compare_of(struct device *dev, void *data)
>>  	return dev->of_node == data;
>>  }
>>  
>> -/* Possible connectors nodes to ignore */
>> -static const struct of_device_id connectors_match[] = {
>> -	{ .compatible = "composite-video-connector" },
>> -	{ .compatible = "svideo-connector" },
>> -	{ .compatible = "hdmi-connector" },
>> -	{ .compatible = "dvi-connector" },
>> -	{}
>> -};
>> -
>> -static int meson_probe_remote(struct platform_device *pdev,
>> -			      struct component_match **match,
>> -			      struct device_node *parent,
>> -			      struct device_node *remote)
>> -{
>> -	struct device_node *ep, *remote_node;
>> -	int count = 1;
>> -
>> -	/* If node is a connector, return and do not add to match table */
>> -	if (of_match_node(connectors_match, remote))
>> -		return 1;
>> -
>> -	component_match_add(&pdev->dev, match, compare_of, remote);
>> -
>> -	for_each_endpoint_of_node(remote, ep) {
>> -		remote_node = of_graph_get_remote_port_parent(ep);
>> -		if (!remote_node ||
>> -		    remote_node == parent || /* Ignore parent endpoint */
>> -		    !of_device_is_available(remote_node)) {
>> -			of_node_put(remote_node);
>> -			continue;
>> -		}
>> -
>> -		count += meson_probe_remote(pdev, match, remote, remote_node);
>> -
>> -		of_node_put(remote_node);
>> -	}
>> -
>> -	return count;
>> -}
>> -
>>  static void meson_drv_shutdown(struct platform_device *pdev)
>>  {
>>  	struct meson_drm *priv = dev_get_drvdata(&pdev->dev);
>> @@ -478,6 +438,13 @@ static void meson_drv_shutdown(struct platform_device *pdev)
>>  	drm_atomic_helper_shutdown(priv->drm);
>>  }
>>  
>> +/* Possible connectors nodes to ignore */
>> +static const struct of_device_id connectors_match[] = {
>> +	{ .compatible = "composite-video-connector" },
>> +	{ .compatible = "svideo-connector" },
>> +	{}
>> +};
>> +
>>  static int meson_drv_probe(struct platform_device *pdev)
>>  {
>>  	struct component_match *match = NULL;
>> @@ -492,8 +459,21 @@ static int meson_drv_probe(struct platform_device *pdev)
>>  			continue;
>>  		}
>>  
>> -		count += meson_probe_remote(pdev, &match, np, remote);
>> +		/* If an analog connector is detected, count it as an output */
>> +		if (of_match_node(connectors_match, remote)) {
>> +			++count;
>> +			of_node_put(remote);
>> +			continue;
>> +		}
>> +
>> +		DRM_DEBUG_DRIVER("parent %pOF remote match add %pOF parent %s\n",
>> +				  np, remote, dev_name(&pdev->dev));
> Avoid the deprecated logging functions.
> Use drm_dbg() or if there is no drm_device just dev_dbg().
> 
> I assume the driver uses DRM_xxx all over, so I understand if you keep
> it as-is.

Since it's in the probe function, I will move to dev_dbg().
I'll probably do a print cleanup all over the driver.

> 
>> +
>> +		component_match_add(&pdev->dev, &match, compare_of, remote);
>> +
>>  		of_node_put(remote);
>> +
>> +		++count;
>>  	}
>>  
>>  	if (count && !match)
>> -- 
>> 2.25.1

Thanks,
Neil