Quoting Laurent Pinchart (2021-12-01 04:38:46)
> Hi Kieran,
>
> Thank you for the patch.
>
> On Tue, Nov 30, 2021 at 04:25:12PM +0000, Kieran Bingham wrote:
> > The bridge probe ordering for DSI devices has been clarified and further
> > documented in
>
> I've read the document and
>
Good, I'm glad you've fully got the
>
> :-)
Sorry, not sure how I missed that, I must have failed to paste in the
link to the DSI probe documentation. But as you've read that, and now
this is squashed, I think this is done anyway.
Thanks for handling the integrations.
--
Kieran
>
> > To support connecting with the SN65DSI86 device after commit c3b75d4734cb
> > ("drm/bridge: sn65dsi86: Register and attach our DSI device at probe"),
> > update to the new probe ordering to remove a perpetual -EPROBE_DEFER
> > loop between the two devices.
> >
> > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> >
> > ---
> > v2
> > - Remove now unused panel variable from rcar_mipi_dsi_probe()
> >
> > drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 49 +++++++++++++------------
> > 1 file changed, 26 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> > index 50e922328fed..0a9f197ef62c 100644
> > --- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> > +++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> > @@ -637,6 +637,8 @@ static int rcar_mipi_dsi_host_attach(struct mipi_dsi_host *host,
> > struct mipi_dsi_device *device)
> > {
> > struct rcar_mipi_dsi *dsi = host_to_rcar_mipi_dsi(host);
> > + struct drm_panel *panel;
> > + int ret;
> >
> > if (device->lanes > dsi->num_data_lanes)
> > return -EINVAL;
> > @@ -644,12 +646,36 @@ static int rcar_mipi_dsi_host_attach(struct mipi_dsi_host *host,
> > dsi->lanes = device->lanes;
> > dsi->format = device->format;
> >
> > + ret = drm_of_find_panel_or_bridge(dsi->dev->of_node, 1, 0, &panel,
> > + &dsi->next_bridge);
> > + if (ret) {
> > + dev_err_probe(dsi->dev, ret, "could not find next bridge\n");
>
> dev_err_probe() should only be used in probe(), and this function isn't
> guaranteed to be called at probe time only.
>
> This isn't a big deal as the next patch fixes this, and both will be
> squashed. Furthermore, rcar_mipi_dsi_host_attach() should only be called
> when the DSI device gets registered, which should happen after it
> registers its bridge, so I don't think we can see a probe deferral here.
>
> Other than that the patch looks fine, I'll squash it with the DSI
> driver.
>
> > + return ret;
> > + }
> > +
> > + if (!dsi->next_bridge) {
> > + dsi->next_bridge = devm_drm_panel_bridge_add(dsi->dev, panel);
> > + if (IS_ERR(dsi->next_bridge)) {
> > + dev_err(dsi->dev, "failed to create panel bridge\n");
> > + return PTR_ERR(dsi->next_bridge);
> > + }
> > + }
> > +
> > + /* Initialize the DRM bridge. */
> > + dsi->bridge.funcs = &rcar_mipi_dsi_bridge_ops;
> > + dsi->bridge.of_node = dsi->dev->of_node;
> > + drm_bridge_add(&dsi->bridge);
> > +
> > return 0;
> > }
> >
> > static int rcar_mipi_dsi_host_detach(struct mipi_dsi_host *host,
> > struct mipi_dsi_device *device)
> > {
> > + struct rcar_mipi_dsi *dsi = host_to_rcar_mipi_dsi(host);
> > +
> > + drm_bridge_remove(&dsi->bridge);
> > +
> > return 0;
> > }
> >
> > @@ -731,7 +757,6 @@ static int rcar_mipi_dsi_get_clocks(struct rcar_mipi_dsi *dsi)
> > static int rcar_mipi_dsi_probe(struct platform_device *pdev)
> > {
> > struct rcar_mipi_dsi *dsi;
> > - struct drm_panel *panel;
> > struct resource *mem;
> > int ret;
> >
> > @@ -764,21 +789,6 @@ static int rcar_mipi_dsi_probe(struct platform_device *pdev)
> > return PTR_ERR(dsi->rstc);
> > }
> >
> > - ret = drm_of_find_panel_or_bridge(dsi->dev->of_node, 1, 0, &panel,
> > - &dsi->next_bridge);
> > - if (ret) {
> > - dev_err_probe(dsi->dev, ret, "could not find next bridge\n");
> > - return ret;
> > - }
> > -
> > - if (!dsi->next_bridge) {
> > - dsi->next_bridge = devm_drm_panel_bridge_add(dsi->dev, panel);
> > - if (IS_ERR(dsi->next_bridge)) {
> > - dev_err(dsi->dev, "failed to create panel bridge\n");
> > - return PTR_ERR(dsi->next_bridge);
> > - }
> > - }
> > -
> > /* Initialize the DSI host. */
> > dsi->host.dev = dsi->dev;
> > dsi->host.ops = &rcar_mipi_dsi_host_ops;
> > @@ -786,11 +796,6 @@ static int rcar_mipi_dsi_probe(struct platform_device *pdev)
> > if (ret < 0)
> > return ret;
> >
> > - /* Initialize the DRM bridge. */
> > - dsi->bridge.funcs = &rcar_mipi_dsi_bridge_ops;
> > - dsi->bridge.of_node = dsi->dev->of_node;
> > - drm_bridge_add(&dsi->bridge);
> > -
> > return 0;
> > }
> >
> > @@ -798,8 +803,6 @@ static int rcar_mipi_dsi_remove(struct platform_device *pdev)
> > {
> > struct rcar_mipi_dsi *dsi = platform_get_drvdata(pdev);
> >
> > - drm_bridge_remove(&dsi->bridge);
> > -
> > mipi_dsi_host_unregister(&dsi->host);
> >
> > return 0;
>
> --
> Regards,
>
> Laurent Pinchart
