Re: [PATCH 1/3] drm/mediatek: move mipi_dsi_host_register to probe

[Jitao Shi <jitao.shi@mediatek.com>]

On Thu, 2019-02-14 at 14:02 +0800, Nicolas Boichat wrote:
> Just some comments on the error path, I'm not sure about the change itself.
> 
> On Thu, Feb 14, 2019 at 12:42 PM Jitao Shi <jitao.shi@mediatek.com> wrote:
> >
> > DSI panel driver need attach function which is inculde in
> > mipi_dsi_host_ops.
> >
> > If mipi_dsi_host_register is not in probe, dsi panel will
> > probe fail or more delay.
> >
> > So move the mipi_dsi_host_register to probe from bind.
> >
> > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dsi.c | 49 ++++++++++++++++++------------
> >  1 file changed, 30 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index 27b507eb4a99..93fa255b4aad 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -1045,12 +1045,6 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> >                 return ret;
> >         }
> >
> > -       ret = mipi_dsi_host_register(&dsi->host);
> > -       if (ret < 0) {
> > -               dev_err(dev, "failed to register DSI host: %d\n", ret);
> > -               goto err_ddp_comp_unregister;
> > -       }
> > -
> >         ret = mtk_dsi_create_conn_enc(drm, dsi);
> >         if (ret) {
> >                 DRM_ERROR("Encoder create failed with %d\n", ret);
> > @@ -1060,8 +1054,6 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> >         return 0;
> >
> >  err_unregister:
> > -       mipi_dsi_host_unregister(&dsi->host);
> > -err_ddp_comp_unregister:
> >         mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
> >         return ret;
> >  }
> > @@ -1097,31 +1089,37 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> >
> >         dsi->host.ops = &mtk_dsi_ops;
> >         dsi->host.dev = dev;
> > +       dsi->dev = dev;
> > +       ret = mipi_dsi_host_register(&dsi->host);
> > +       if (ret < 0) {
> > +               dev_err(dev, "failed to register DSI host: %d\n", ret);
> > +               return -EPROBE_DEFER;
> 
> return ret
> 

Ok, I'll fix it next version.

> > +       }
> >
> >         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> >                                           &dsi->panel, &dsi->bridge);
> >         if (ret)
> > -               return ret;
> > +               goto err_unregister_host;
> >
> >         dsi->engine_clk = devm_clk_get(dev, "engine");
> >         if (IS_ERR(dsi->engine_clk)) {
> >                 ret = PTR_ERR(dsi->engine_clk);
> >                 dev_err(dev, "Failed to get engine clock: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         dsi->digital_clk = devm_clk_get(dev, "digital");
> >         if (IS_ERR(dsi->digital_clk)) {
> >                 ret = PTR_ERR(dsi->digital_clk);
> >                 dev_err(dev, "Failed to get digital clock: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         dsi->hs_clk = devm_clk_get(dev, "hs");
> >         if (IS_ERR(dsi->hs_clk)) {
> >                 ret = PTR_ERR(dsi->hs_clk);
> >                 dev_err(dev, "Failed to get hs clock: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > @@ -1129,33 +1127,35 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> >         if (IS_ERR(dsi->regs)) {
> >                 ret = PTR_ERR(dsi->regs);
> >                 dev_err(dev, "Failed to ioremap memory: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         dsi->phy = devm_phy_get(dev, "dphy");
> >         if (IS_ERR(dsi->phy)) {
> >                 ret = PTR_ERR(dsi->phy);
> >                 dev_err(dev, "Failed to get MIPI-DPHY: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DSI);
> >         if (comp_id < 0) {
> >                 dev_err(dev, "Failed to identify by alias: %d\n", comp_id);
> > -               return comp_id;
> > +               ret = comp_id;
> > +               goto err_unregister_host;
> >         }
> >
> >         ret = mtk_ddp_comp_init(dev, dev->of_node, &dsi->ddp_comp, comp_id,
> >                                 &mtk_dsi_funcs);
> >         if (ret) {
> >                 dev_err(dev, "Failed to initialize component: %d\n", ret);
> > -               return ret;
> > +               goto err_unregister_host;
> >         }
> >
> >         irq_num = platform_get_irq(pdev, 0);
> >         if (irq_num < 0) {
> >                 dev_err(&pdev->dev, "failed to request dsi irq resource\n");
> > -               return -EPROBE_DEFER;
> > +               ret = -EPROBE_DEFER;
> 
> I think you need to do ret = irq_num here, too (and yes, it was
> probably wrong before?)
> 

Yes, the "ret = irq_num" is right. 
We regard all the return error case as "-EPROBE_DEFER".

Actually the error case (ex. EXIO) should return error case.

I'll fix it next version.

> > +               goto err_unregister_host;
> >         }
> >
> >         irq_set_status_flags(irq_num, IRQ_TYPE_LEVEL_LOW);
> > @@ -1163,14 +1163,25 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> >                                IRQF_TRIGGER_LOW, dev_name(&pdev->dev), dsi);
> >         if (ret) {
> >                 dev_err(&pdev->dev, "failed to request mediatek dsi irq\n");
> > -               return -EPROBE_DEFER;
> > +               ret = -EPROBE_DEFER;
> 
> Ditto, I'd not reassign ret.

I'll fix it next version.
> 
> > +               goto err_unregister_host;
> >         }
> >
> >         init_waitqueue_head(&dsi->irq_wait_queue);
> >
> >         platform_set_drvdata(pdev, dsi);
> >
> > -       return component_add(&pdev->dev, &mtk_dsi_component_ops);
> > +       ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
> > +       if (ret) {
> > +               ret = -EPROBE_DEFER;
> 
> Ditto (this one _was_ right before).

I'll fix it next version.

> 
> > +               goto err_unregister_host;
> > +       }
> > +
> > +       return 0;
> > +
> > +err_unregister_host:
> > +       mipi_dsi_host_unregister(&dsi->host);
> > +       return ret;
> >  }
> >
> >  static int mtk_dsi_remove(struct platform_device *pdev)
> > --
> > 2.20.1
> >



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