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Message-ID: <31bff2df-40a1-21f7-e155-38028b2688e8@quicinc.com>
Date:   Wed, 27 Sep 2023 08:25:26 -0700
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Subject: Re: [PATCH v3 1/7] drm/msm/dp: tie dp_display_irq_handler() with dp
 driver
Content-Language: en-US
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     <dri-devel@lists.freedesktop.org>, <robdclark@gmail.com>,
        <sean@poorly.run>, <swboyd@chromium.org>, <dianders@chromium.org>,
        <vkoul@kernel.org>, <daniel@ffwll.ch>, <airlied@gmail.com>,
        <agross@kernel.org>, <andersson@kernel.org>,
        <quic_abhinavk@quicinc.com>, <quic_jesszhan@quicinc.com>,
        <quic_sbillaka@quicinc.com>, <marijn.suijten@somainline.org>,
        <freedreno@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1694813901-26952-1-git-send-email-quic_khsieh@quicinc.com>
 <1694813901-26952-2-git-send-email-quic_khsieh@quicinc.com>
 <CAA8EJprRFYMF-6yxcL75rftfii0kt7hmg_+TeOMJw+BRyDYdeg@mail.gmail.com>
 <1c82a0a6-d85f-9800-bdc4-2a4892b4239b@quicinc.com>
 <CAA8EJpoW8COZD7+yg9oZ=k=x36+XQKaJgvhab=XZPwTVuixh2A@mail.gmail.com>
From:   Kuogee Hsieh <quic_khsieh@quicinc.com>
In-Reply-To: <CAA8EJpoW8COZD7+yg9oZ=k=x36+XQKaJgvhab=XZPwTVuixh2A@mail.gmail.com>
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On 9/23/2023 11:45 AM, Dmitry Baryshkov wrote:
> On Sat, 23 Sept 2023 at 02:03, Kuogee Hsieh <quic_khsieh@quicinc.com> wrote:
>>
>> On 9/15/2023 5:29 PM, Dmitry Baryshkov wrote:
>>> On Sat, 16 Sept 2023 at 00:38, Kuogee Hsieh <quic_khsieh@quicinc.com> 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@quicinc.com>
>>>> ---
>>>>    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
>>>>
>
>