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

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

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@quicinc.com>
>>>>> ---
>>>>>   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