Re: [PATCH v6 05/11] drm/hisilicon: Add vblank driver for ADE

[Archit Taneja <architt@codeaurora.org>]

On 3/1/2016 3:44 PM, Xinliang Liu wrote:
> Hi,
>
> On 1 March 2016 at 02:48, Archit Taneja <architt@codeaurora.org> wrote:
>>
>>
>> On 2/26/2016 2:10 PM, Xinliang Liu wrote:
>>>
>>> Add vblank irq handle.
>>>
>>> v6: None.
>>> v5: None.
>>> v4: None.
>>> v3:
>>> - Remove hisi_get_crtc_from_index func.
>>> - A few cleanup.
>>> v2:
>>> - Remove abtraction layer.
>>>
>>> Signed-off-by: Xinliang Liu <xinliang.liu@linaro.org>
>>> ---
>>>    drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 62
>>> +++++++++++++++++++++++++
>>>    drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c | 14 +++++-
>>>    2 files changed, 75 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
>>> b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
>>> index aa2cf75cab39..749382952ab7 100644
>>> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
>>> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
>>> @@ -292,6 +292,59 @@ static void ade_set_medianoc_qos(struct ade_crtc
>>> *acrtc)
>>>                             SOCKET_QOS_EN, SOCKET_QOS_EN);
>>>    }
>>>
>>> +static int ade_enable_vblank(struct drm_device *dev, unsigned int pipe)
>>> +{
>>> +       struct kirin_drm_private *priv = dev->dev_private;
>>> +       struct ade_crtc *acrtc = to_ade_crtc(priv->crtc[pipe]);
>>> +       struct ade_hw_ctx *ctx = acrtc->ctx;
>>> +       void __iomem *base = ctx->base;
>>> +
>>> +       if (!ctx->power_on)
>>> +               (void)ade_power_up(ctx);
>>> +
>>> +       ade_update_bits(base + LDI_INT_EN, FRAME_END_INT_EN_OFST,
>>> +                       MASK(1), 1);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static void ade_disable_vblank(struct drm_device *dev, unsigned int pipe)
>>> +{
>>> +       struct kirin_drm_private *priv = dev->dev_private;
>>> +       struct ade_crtc *acrtc = to_ade_crtc(priv->crtc[pipe]);
>>> +       struct ade_hw_ctx *ctx = acrtc->ctx;
>>> +       void __iomem *base = ctx->base;
>>> +
>>> +       if (!ctx->power_on) {
>>> +               DRM_ERROR("power is down! vblank disable fail\n");
>>> +               return;
>>> +       }
>>> +
>>> +       ade_update_bits(base + LDI_INT_EN, FRAME_END_INT_EN_OFST,
>>> +                       MASK(1), 0);
>>> +}
>>> +
>>> +static irqreturn_t ade_irq_handler(int irq, void *data)
>>> +{
>>> +       struct ade_crtc *acrtc = data;
>>> +       struct ade_hw_ctx *ctx = acrtc->ctx;
>>> +       struct drm_crtc *crtc = &acrtc->base;
>>> +       void __iomem *base = ctx->base;
>>> +       u32 status;
>>> +
>>> +       status = readl(base + LDI_MSK_INT);
>>> +       DRM_DEBUG_VBL("LDI IRQ: status=0x%X\n", status);
>>> +
>>> +       /* vblank irq */
>>> +       if (status & BIT(FRAME_END_INT_EN_OFST)) {
>>> +               ade_update_bits(base + LDI_INT_CLR, FRAME_END_INT_EN_OFST,
>>> +                               MASK(1), 1);
>>> +               drm_crtc_handle_vblank(crtc);
>>> +       }
>>> +
>>> +       return IRQ_HANDLED;
>>> +}
>>> +
>>>    static void ade_display_enable(struct ade_crtc *acrtc)
>>>    {
>>>          struct ade_hw_ctx *ctx = acrtc->ctx;
>>> @@ -967,6 +1020,15 @@ int ade_drm_init(struct drm_device *dev)
>>>          if (ret)
>>>                  return ret;
>>>
>>> +       /* vblank irq init */
>>> +       ret = devm_request_irq(dev->dev, ctx->irq, ade_irq_handler,
>>> +                              DRIVER_IRQ_SHARED, dev->driver->name,
>>> acrtc);
>>
>>
>> This isn't the way we set up interrupts for kms drivers. We need to
>> provide the handler in drm_driver and call drm_irq_install.
>
> I prefer to set up interrupts here for two reasons.
> One is that it is easy to pass any interrupt private "void * data" to
> the interrupt handler here.
> As I discussed with Daniel Vetter before: https://lkml.org/lkml/2015/9/10/204.
>
> Second is setting up interrupt here in the specific SoC display
> controller driver, make other SoC reuse the kirin_drm_drv.c code
> easily.
> Different Hisilicon SoC may has different display controller interrupts.

Sure, as long as this has been discussed before.

>
>>
>>
>>> +       if (ret)
>>> +               return ret;
>>> +       dev->driver->get_vblank_counter = drm_vblank_no_hw_counter;
>>> +       dev->driver->enable_vblank = ade_enable_vblank;
>>> +       dev->driver->disable_vblank = ade_disable_vblank;
>>> +
>>>          return 0;
>>>    }
>>>
>>> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
>>> b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
>>> index 055729c1889c..723888feb760 100644
>>> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
>>> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
>>> @@ -32,6 +32,7 @@ static int kirin_drm_kms_cleanup(struct drm_device *dev)
>>>    {
>>>          struct kirin_drm_private *priv = dev->dev_private;
>>>
>>> +       drm_vblank_cleanup(dev);
>>>          dc_ops->cleanup(dev);
>>>          drm_mode_config_cleanup(dev);
>>>          devm_kfree(dev->dev, priv);
>>> @@ -85,11 +86,22 @@ static int kirin_drm_kms_init(struct drm_device *dev)
>>>                  goto err_dc_cleanup;
>>>          }
>>>
>>> +       /* vblank init */
>>> +       ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
>>> +       if (ret) {
>>> +               DRM_ERROR("failed to initialize vblank.\n");
>>> +               goto err_unbind_all;
>>> +       }
>>> +       /* with irq_enabled = true, we can use the vblank feature. */
>>> +       dev->irq_enabled = true;
>>> +
>>>          /* reset all the states of crtc/plane/encoder/connector */
>>>          drm_mode_config_reset(dev);
>>>
>>>          return 0;
>>>
>>> +err_unbind_all:
>>> +       component_unbind_all(dev->dev, dev);
>>>    err_dc_cleanup:
>>>          dc_ops->cleanup(dev);
>>>    err_mode_config_cleanup:
>>> @@ -123,7 +135,7 @@ static int kirin_gem_cma_dumb_create(struct drm_file
>>> *file,
>>>
>>>    static struct drm_driver kirin_drm_driver = {
>>>          .driver_features        = DRIVER_GEM | DRIVER_MODESET |
>>> DRIVER_PRIME |
>>> -                                 DRIVER_ATOMIC,
>>> +                                 DRIVER_ATOMIC | DRIVER_HAVE_IRQ,
>>
>>
>> DRIVER_IRQ_SHARED should be added here if you want IRQF_SHARED flag set
>> when requesting the handler.
>
> If not using the drm_irq_install to set up interrupts,
> DRIVER_IRQ_SHARED may not be required to set.
>

Yes. In any case, you should use IRQF_SHARED and not DRIVER_IRQ_SHARED
in the call to devm_request_irq(). The latter is a drm flag meant to be
used only for driver_features.

Thanks,
Archit

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