[PATCH] drm/mipi: set fwnode when a mipi_dsi_device registers itself

[PATCH] drm/mipi: set fwnode when a mipi_dsi_device registers itself

[Will McVicker]

This is needed for fw_devlink to work properly with MIPI DSI devices.
Without setting the device's fwnode, the sync state framework isn't able
to properly track device links between the MIPI DSI device and its
suppliers which may result in its supplier probing before the mipi
device.

Suggested-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Will McVicker <willmcvicker@google.com>
---
 drivers/gpu/drm/drm_mipi_dsi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 5dd475e82995..469d56cf2a50 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -222,6 +222,7 @@ mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 	}
 
 	dsi->dev.of_node = info->node;
+	dsi->dev.fwnode = of_fwnode_handle(info->node);
 	dsi->channel = info->channel;
 	strlcpy(dsi->name, info->type, sizeof(dsi->name));
 
-- 
2.32.0.93.g670b81a890-goog

Re: [PATCH] drm/mipi: set fwnode when a mipi_dsi_device registers itself

[Saravana Kannan]

Hi William,

Thanks for catching this.

On Fri, Jul 9, 2021 at 11:45 PM Will McVicker <willmcvicker@google.com> wrote:
>
> This is needed for fw_devlink to work properly with MIPI DSI devices.
> Without setting the device's fwnode, the sync state framework isn't able
> to properly track device links between the MIPI DSI device and its
> suppliers which may result in its supplier probing before the mipi
> device.

I think it'd be more accurate if the commit text is something like:

drm/mipi: set fwnode when a mipi_dsi_device is registered

This allows the fw_devlink feature to work across mipi_dsi bus devices too. This
feature avoid unnecessary probe deferrals of mipi_dsi devices, defers
consumers of
mipi_dsi devices till the mipi_dsi devices probe, and allows mipi_dsi drivers to
implement sync_state() callbacks.

Reviewed-by: Saravana Kannan <saravanak@google.com>

Thanks,
Saravana

>
> Suggested-by: Saravana Kannan <saravanak@google.com>
> Signed-off-by: Will McVicker <willmcvicker@google.com>
> ---
>  drivers/gpu/drm/drm_mipi_dsi.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 5dd475e82995..469d56cf2a50 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -222,6 +222,7 @@ mipi_dsi_device_register_full(struct mipi_dsi_host *host,
>         }
>
>         dsi->dev.of_node = info->node;
> +       dsi->dev.fwnode = of_fwnode_handle(info->node);
>         dsi->channel = info->channel;
>         strlcpy(dsi->name, info->type, sizeof(dsi->name));
>
> --
> 2.32.0.93.g670b81a890-goog
>