Re: [PATCH v3 1/7] drm/msm/dp: tie dp_display_irq_handler() with dp driver

[Kuogee Hsieh]

On 9/23/2023 11:45 AM, Dmitry Baryshkov wrote:
> On Sat, 23 Sept 2023 at 02:03, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
> > On 9/15/2023 5:29 PM, Dmitry Baryshkov wrote:
> > > On Sat, 16 Sept 2023 at 00:38, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
> > > > Currently the dp_display_irq_handler() is executed at msm_dp_modeset_init()
> > > > which ties irq registration to the DPU device's life cycle, while depending on
> > > > resources that are released as the DP device is torn down. Move register DP
> > > > driver irq handler at dp_display_probe() to have dp_display_irq_handler()
> > > > is tied with DP device.
> > > >
> > > > Changes in v3:
> > > > -- move calling dp_display_irq_handler() to probe
> > > Was there a changelog for the previous reivions? What is the
> > > difference between v1 and v2?
> > >
> > > > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > > > ---
> > > >    drivers/gpu/drm/msm/dp/dp_display.c | 35 +++++++++++++----------------------
> > > >    drivers/gpu/drm/msm/dp/dp_display.h |  1 -
> > > >    2 files changed, 13 insertions(+), 23 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > > > index 76f1395..c217430 100644
> > > > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > > > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > > > @@ -1193,30 +1193,23 @@ 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) {
> > > What is the point in this check?
> > >
> > > > -               DRM_ERROR("failed to get irq\n");
> > > > -               return -EINVAL;
> > > > +               dp->irq = platform_get_irq(dp->pdev, 0);
> > > > +               if (!dp->irq) {
> > > > +                       DRM_ERROR("failed to get irq\n");
> > > > +                       return -EINVAL;
> > > > +               }
> > > >           }
> > > >
> > > > -       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",
> > > > -                               dp->irq, rc);
> > > > +               DRM_ERROR("failed to request IRQ%u: %d\n", dp->irq, rc);
> > > >                   return rc;
> > > >           }
> > > >
> > > > @@ -1287,6 +1280,10 @@ static int dp_display_probe(struct platform_device *pdev)
> > > >
> > > >           platform_set_drvdata(pdev, &dp->dp_display);
> > > >
> > > > +       rc = dp_display_request_irq(dp);
> > > > +       if (rc)
> > > > +               return rc;
> > > This way the IRQ ends up being enabled in _probe. Are we ready to
> > > handle it here? Is the DP device fully setup at this moment?
> > The irq is enabled here.
> >
> > but DP driver hpd hardware block has not yet be enabled. this means no
> > irq will be delivered.
> There are other IRQ kinds, not only just HPD ones.

pm_runtime_resume_and_get() will enable host controller (including hpd and aux block).
so that as long as pm_runtime_resume_and_get() called, then all DP related interrupts will be handled accordingly.

> >    .hpd_enable() will call pm_runtime_resume_and_get() and
> > dp_catalog_ctrl_hpd_enable().
> >
> > after .hpd_enable() irq will be delivered and handled properly.
> >
> >
> >
> > > > +
> > > >           rc = component_add(&pdev->dev, &dp_display_comp_ops);
> > > >           if (rc) {
> > > >                   DRM_ERROR("component add failed, rc=%d\n", rc);
> > > > @@ -1549,12 +1546,6 @@ 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);
> > > > --
> > > > 2.7.4