Re: [PATCH v1 4/5] drm/msm/dp: move relevant dp initialization code from bind() to probe()

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On 17/07/2023 20:16, Kuogee Hsieh wrote:
> On 7/10/2023 11:13 AM, Dmitry Baryshkov wrote:
> > On 10/07/2023 19:57, Kuogee Hsieh wrote:
> > > On 7/7/2023 5:11 PM, Dmitry Baryshkov wrote:
> > > > On 08/07/2023 02:52, Kuogee Hsieh wrote:
> > > > > In preparation of moving edp of_dp_aux_populate_bus() to
> > > > > dp_display_probe(), move dp_display_request_irq(),
> > > > > dp->parser->parse() and dp_power_client_init() to dp_display_probe()
> > > > > too.
> > > > >
> > > > > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > > > > ---
> > > > >   drivers/gpu/drm/msm/dp/dp_display.c | 48 
> > > > > +++++++++++++++++--------------------
> > > > >   drivers/gpu/drm/msm/dp/dp_display.h |  1 -
> > > > >   2 files changed, 22 insertions(+), 27 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c 
> > > > > b/drivers/gpu/drm/msm/dp/dp_display.c
> > > > > index 44580c2..185f1eb 100644
> > > > > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > > > > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > > > > @@ -290,12 +290,6 @@ static int dp_display_bind(struct device *dev, 
> > > > > struct device *master,
> > > > >           goto end;
> > > > >       }
> > > > >   -    rc = dp_power_client_init(dp->power);
> > > > > -    if (rc) {
> > > > > -        DRM_ERROR("Power client create failed\n");
> > > > > -        goto end;
> > > > > -    }
> > > > > -
> > > > >       rc = dp_register_audio_driver(dev, dp->audio);
> > > > >       if (rc) {
> > > > >           DRM_ERROR("Audio registration Dp failed\n");
> > > > > @@ -752,6 +746,12 @@ static int dp_init_sub_modules(struct 
> > > > > dp_display_private *dp)
> > > > >           goto error;
> > > > >       }
> > > > >   +    rc = dp->parser->parse(dp->parser);
> > > > > +    if (rc) {
> > > > > +        DRM_ERROR("device tree parsing failed\n");
> > > > > +        goto error;
> > > > > +    }
> > > > > +
> > > > >       dp->catalog = dp_catalog_get(dev, &dp->parser->io);
> > > > >       if (IS_ERR(dp->catalog)) {
> > > > >           rc = PTR_ERR(dp->catalog);
> > > > > @@ -768,6 +768,12 @@ static int dp_init_sub_modules(struct 
> > > > > dp_display_private *dp)
> > > > >           goto error;
> > > > >       }
> > > > >   +    rc = dp_power_client_init(dp->power);
> > > > > +    if (rc) {
> > > > > +        DRM_ERROR("Power client create failed\n");
> > > > > +        goto error;
> > > > > +    }
> > > > > +
> > > > >       dp->aux = dp_aux_get(dev, dp->catalog, dp->dp_display.is_edp);
> > > > >       if (IS_ERR(dp->aux)) {
> > > > >           rc = PTR_ERR(dp->aux);
> > > > > @@ -1196,26 +1202,20 @@ static irqreturn_t 
> > > > > dp_display_irq_handler(int irq, void *dev_id)
> > > > >       return ret;
> > > > >   }
> > > > >   -int dp_display_request_irq(struct msm_dp *dp_display)
> > > > > +static int dp_display_request_irq(struct dp_display_private *dp)
> > > > >   {
> > > > >       int rc = 0;
> > > > > -    struct dp_display_private *dp;
> > > > > -
> > > > > -    if (!dp_display) {
> > > > > -        DRM_ERROR("invalid input\n");
> > > > > -        return -EINVAL;
> > > > > -    }
> > > > > -
> > > > > -    dp = container_of(dp_display, struct dp_display_private, 
> > > > > dp_display);
> > > > > +    struct device *dev = &dp->pdev->dev;
> > > > >   -    dp->irq = irq_of_parse_and_map(dp->pdev->dev.of_node, 0);
> > > > >       if (!dp->irq) {
> > > > > -        DRM_ERROR("failed to get irq\n");
> > > > > -        return -EINVAL;
> > > > > +        dp->irq = irq_of_parse_and_map(dp->pdev->dev.of_node, 0);
> > > > > +        if (!dp->irq) {
> > > > > +            DRM_ERROR("failed to get irq\n");
> > > > > +            return -EINVAL;
> > > > > +        }
> > > > >       }
> > > >
> > > > Use platform_get_irq() from probe() function.
> > > >
> > > > >   -    rc = devm_request_irq(dp_display->drm_dev->dev, dp->irq,
> > > > > -            dp_display_irq_handler,
> > > > > +    rc = devm_request_irq(dev, dp->irq, dp_display_irq_handler,
> > > > >               IRQF_TRIGGER_HIGH, "dp_display_isr", dp);
> > > >
> > > >
> > > > >       if (rc < 0) {
> > > > >           DRM_ERROR("failed to request IRQ%u: %d\n",
> > > > > @@ -1290,6 +1290,8 @@ static int dp_display_probe(struct 
> > > > > platform_device *pdev)
> > > > >         platform_set_drvdata(pdev, &dp->dp_display);
> > > > >   +    dp_display_request_irq(dp);
> > > > > +
> > > >
> > > > Error checking?
> > > > Are we completely ready to handle interrupts at this point?
> > > not until dp_display_host_init() is called which will be called from 
> > > pm_runtime_resume() later.
> >
> > But once you request_irq(), you should be ready for the IRQs to be 
> > delivered right away.
>
> At this point, the DP controller interrupts mask bit is not enabled yet.
>
> Therefore interrupts will not happen until dp_bridge_hpd_enable() is 
> called to initialize dp host  controller and then enabled mask bits.

Are AUX and CTRL interrupts also disabled? What about any stray/pending 
interrupts? Just take it as a rule of thumb. Once request_irq() has been 
called without the IRQ_NOAUTOEN flag, the driver should be prepared to 
handle the incoming interrupt requests.

> > > > >       rc = component_add(&pdev->dev, &dp_display_comp_ops);
> > > > >       if (rc) {
> > > > >           DRM_ERROR("component add failed, rc=%d\n", rc);
> > > > > @@ -1574,12 +1576,6 @@ int msm_dp_modeset_init(struct msm_dp 
> > > > > *dp_display, struct drm_device *dev,
> > > > >         dp_priv = container_of(dp_display, struct 
> > > > > dp_display_private, dp_display);
> > > > >   -    ret = dp_display_request_irq(dp_display);
> > > > > -    if (ret) {
> > > > > -        DRM_ERROR("request_irq failed, ret=%d\n", ret);
> > > > > -        return ret;
> > > > > -    }
> > > > > -
> > > > >       ret = dp_display_get_next_bridge(dp_display);
> > > > >       if (ret)
> > > > >           return ret;
> > > > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.h 
> > > > > b/drivers/gpu/drm/msm/dp/dp_display.h
> > > > > index 1e9415a..b3c08de 100644
> > > > > --- a/drivers/gpu/drm/msm/dp/dp_display.h
> > > > > +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> > > > > @@ -35,7 +35,6 @@ struct msm_dp {
> > > > >   int dp_display_set_plugged_cb(struct msm_dp *dp_display,
> > > > >           hdmi_codec_plugged_cb fn, struct device *codec_dev);
> > > > >   int dp_display_get_modes(struct msm_dp *dp_display);
> > > > > -int dp_display_request_irq(struct msm_dp *dp_display);
> > > > >   bool dp_display_check_video_test(struct msm_dp *dp_display);
> > > > >   int dp_display_get_test_bpp(struct msm_dp *dp_display);
> > > > >   void dp_display_signal_audio_start(struct msm_dp *dp_display);

--
With best wishes
Dmitry