Hi Jagan

@@ -1503,28 +1506,18 @@ static int samsung_dsim_panel_or_bridge(struct

samsung_dsim *dsi,
 {
        struct drm_bridge *panel_bridge;
        struct drm_panel *panel;
-       struct device_node *remote;
-
-       if (of_graph_is_present(node)) {
-               remote = of_graph_get_remote_node(node, DSI_PORT_OUT, 0);
-               if (!remote)
-                       return -ENODEV;
+       int ret;

-               node = remote;
-       }
+       ret = drm_of_find_panel_or_bridge(dsi->dev->of_node, 1, 0, &panel,
+                                         &panel_bridge);
+       if (ret)
+               return ret;

-       panel_bridge = of_drm_find_bridge(node);
-       if (!panel_bridge) {
-               panel = of_drm_find_panel(node);
-               if (!IS_ERR(panel)) {
-                       panel_bridge = drm_panel_bridge_add(panel);
-                       if (IS_ERR(panel_bridge))
-                               return PTR_ERR(panel_bridge);
-               }
+       if (panel) {
+               panel_bridge = drm_panel_bridge_add(panel);
+               if (IS_ERR(panel_bridge))
+                       return PTR_ERR(panel_bridge);
        }
-
-       of_node_put(node);
-
        dsi->out_bridge = panel_bridge;

I need to apply this change to register my panel on imx8mn even mode I
found that

@@ -1594,11 +1587,15 @@ static int samsung_dsim_host_attach(struct

mipi_dsi_host *host,
                        return ret;
        }

-       mutex_lock(&drm->mode_config.mutex);

        dsi->lanes = device->lanes;
        dsi->format = device->format;
        dsi->mode_flags = device->mode_flags;
+
+       if (!drm)
+               return 0;
+
+       mutex_lock(&drm->mode_config.mutex);

mode_config is not initialized in this path.

Michael



On Tue, Nov 30, 2021 at 8:39 AM Jagan Teki [off-list ref] wrote:

On Fri, Nov 26, 2021 at 9:34 PM Maxime Ripard [off-list ref] wrote:

quoted

On Thu, Nov 25, 2021 at 09:44:14PM +0530, Jagan Teki wrote:

quoted

On Thu, Nov 25, 2021 at 9:40 PM Maxime Ripard [off-list ref] wrote:

quoted

On Thu, Nov 25, 2021 at 07:55:41PM +0530, Jagan Teki wrote:

quoted

Hi,

On Thu, Nov 25, 2021 at 7:45 PM Maxime Ripard [off-list ref] wrote:

quoted

On Wed, Nov 24, 2021 at 12:02:47AM +0530, Jagan Teki wrote:

quoted

quoted

quoted

quoted

quoted

quoted

+     dsi->panel = of_drm_find_panel(remote);
+     if (IS_ERR(dsi->panel)) {
+             dsi->panel = NULL;
+
+             dsi->next_bridge = of_drm_find_bridge(remote);
+             if (IS_ERR(dsi->next_bridge)) {
+                     dev_err(dsi->dev, "failed to find bridge\n");
+                     return PTR_ERR(dsi->next_bridge);
+             }
+     } else {
+             dsi->next_bridge = NULL;
+     }
+
+     of_node_put(remote);

Using devm_drm_of_get_bridge would greatly simplify the driver

I'm aware of this and this would break the existing sunxi dsi binding,
we are not using ports based pipeline in dsi node. Of-course you have
pointed the same before, please check below
https://patchwork.kernel.org/project/dri-devel/patch/20210322140152.101709-2-jagan@amarulasolutions.com/

Then drm_of_find_panel_or_bridge needs to be adjusted to handle the DSI
bindings and look for a panel or bridge not only through the OF graph,
but also on the child nodes

Okay. I need to check this.

devm_drm_of_get_bridge is not working with legacy binding like the one
used in sun6i dsi

There's nothing legacy about it.

What I'm mean legacy here with current binding used in sun6i-dsi like this.

&dsi {
          vcc-dsi-supply = <&reg_dcdc1>; /* VCC-DSI */
          status = "okay";

         panel@0 {
                   compatible = "bananapi,s070wv20-ct16-icn6211";
                   reg = <0>;
                   reset-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /*
LCD-RST: PL5 */
                  enable-gpios = <&pio 1 7 GPIO_ACTIVE_HIGH>; /*
LCD-PWR-EN: PB7 */
                  backlight = <&backlight>;
        };
};

Yes, I know, it's the generic DSI binding. It's still not legacy.

quoted

devm_drm_of_get_bridge cannot find the device with above binding and
able to find the device with below binding.

&dsi {
       vcc-dsi-supply = <&reg_dcdc1>; /* VCC-DSI */
       status = "okay";

      ports {
            #address-cells = <1>;
            #size-cells = <0>;

           dsi_out: port@0 {
                   reg = <0>;

                  dsi_out_bridge: endpoint {
                            remote-endpoint = <&bridge_out_dsi>;
                  };
           };
      };

      panel@0 {
             compatible = "bananapi,s070wv20-ct16-icn6211";
             reg = <0>;
             reset-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* LCD-RST: PL5 */
             enable-gpios = <&pio 1 7 GPIO_ACTIVE_HIGH>; /* LCD-PWR-EN: PB7 */
             backlight = <&backlight>;

              port {
                        bridge_out_dsi: endpoint {
                                remote-endpoint = <&dsi_out_bridge>;
                        };
                };
       };
};

Yes, I know, and that's because ...

Okay. I will use find panel and bridge separately instead of
devm_drm_of_get_bridge in version patches.

That's not been my point, at all?

I mean, that whole discussion has been because you shouldn't do that.

quoted

quoted

quoted

quoted

quoted

https://patchwork.kernel.org/project/dri-devel/patch/20211122065223.88059-6-jagan@amarulasolutions.com/

dsi->next_bridge = devm_drm_of_get_bridge(dsi->dev, dsi->dev->of_node, 0, 0);
if (IS_ERR(dsi->next_bridge))
           return PTR_ERR(dsi->next_bridge);

It is only working if we have ports on the pipeline, something like this
https://patchwork.kernel.org/project/dri-devel/patch/20210214194102.126146-8-jagan@amarulasolutions.com/

Please have a look and let me know if I miss anything?

Yes, you're missing the answer you quoted earlier:

Yes, I'm trying to resolve the comment one after another. Will get back.

... You've ignored that comment.

Not understand which comment you mean. There are few about bridge
conversion details, I will send my comments.

The one that got quoted there and you removed. For reference:

quoted

Then drm_of_find_panel_or_bridge needs to be adjusted to handle the DSI
bindings and look for a panel or bridge not only through the OF graph,
but also on the child nodes

devm_drm_of_get_bridge uses drm_of_find_panel_or_bridge under the hood,
so of course it won't find it if drm_of_find_panel_or_bridge doesn't.
You need to modify drm_of_find_panel_or_bridge to also look for child
devices and see if there's a panel or bridge registered for that child
node. Then devm_drm_of_get_bridge will work as you intend it to.

Got it now, I will make necessary changes.

Thanks,
Jagan.

-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael@amarulasolutions.com
__________________________________

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Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
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info@amarulasolutions.com
www.amarulasolutions.com

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