16.06.2020 04:26, Laurent Pinchart пишет:
> Hi Dmitry,
>
> Thank you for the patch.
>
> On Sun, Jun 14, 2020 at 08:22:30PM +0300, Dmitry Osipenko wrote:
>> When graph isn't defined in a device-tree, the of_graph_get_remote_node()
>> prints a noisy error message, telling that port node is not found. This is
>> undesirable behaviour in our case because absence of a panel/bridge graph
>> is a valid case. Let's check presence of the local port in a device-tree
>> before proceeding with parsing the graph.
>>
>> Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>> ---
>> drivers/gpu/drm/drm_of.c | 13 ++++++++++++-
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
>> index b50b44e76279..e0652c38f357 100644
>> --- a/drivers/gpu/drm/drm_of.c
>> +++ b/drivers/gpu/drm/drm_of.c
>> @@ -239,13 +239,24 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
>> struct drm_bridge **bridge)
>> {
>> int ret = -EPROBE_DEFER;
>> - struct device_node *remote;
>> + struct device_node *local, *remote;
>>
>> if (!panel && !bridge)
>> return -EINVAL;
>> if (panel)
>> *panel = NULL;
>>
>> + /*
>> + * of_graph_get_remote_node() produces a noisy error message if port
>> + * node isn't found and the absence of the port is a legit case here,
>> + * so at first we silently check presence of the local port.
>> + */
>> + local = of_graph_get_local_port(np);
>> + if (!local)
>> + return -ENODEV;
>> +
>> + of_node_put(local);
>> +
>
> The code looks fine, but you may want to take into account my proposal
> in 1/7 to instead create a of_graph_has_port() function. The could would
> be simpler here.
>
>> remote = of_graph_get_remote_node(np, port, endpoint);
>> if (!remote)
>> return -ENODEV;
>
I like yours proposals and will prepare v8 based on them, thanks!
