Re: [PATCH v3] drm/bridge: sn65dsi86: defer if there is no dsi host

From: Stephen Boyd
Date: Tue Dec 07 2021 - 23:44:03 EST


Quoting Rob Clark (2021-12-07 13:57:52)
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> Otherwise we don't get another shot at it if the bridge probes before
> the dsi host is registered. It seems like this is what *most* (but not
> all) of the other bridges do.
>
> It looks like this was missed in the conversion to attach dsi host at
> probe time.
>
> Fixes: c3b75d4734cb ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe")
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> ---

Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>

One more nit below

> v2: Drop DRM_ERROR() in favor of drm_err_probe() and shift around the
> spot where we report the error
> v3: Add \n and cull error msgs a bit further
>
> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index 02b490671f8f..c2928a6409b1 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -740,10 +736,8 @@ static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
> pdata->dsi = dsi;
>
> ret = devm_mipi_dsi_attach(dev, dsi);
> - if (ret < 0) {
> - DRM_ERROR("failed to attach dsi to host\n");
> + if (ret < 0)
> return ret;
> - }
>
> return 0;

This can be simplified further to

return devm_mipi_dsi_attach(dev, dsi);