[PATCH 1/2] drm: Stop using drm_vblank_count() as the hw frame counter

[Vincent ABRIOU]

On 10/02/2015 02:48 PM, Ville Syrjälä wrote:
> On Fri, Oct 02, 2015 at 10:25:27AM +0200, Vincent ABRIOU wrote:
>>
>>
>> On 09/30/2015 04:14 PM, Ville Syrjälä wrote:
>>> On Wed, Sep 30, 2015 at 04:08:02PM +0200, Daniel Vetter wrote:
>>>> On Wed, Sep 30, 2015 at 04:46:48PM +0300, ville.syrjala at linux.intel.com wrote:
>>>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>>>>
>>>>> drm_vblank_count() returns the software counter. We should not pretend
>>>>> it's the hw counter since we use the hw counter to figuere out what the
>>>>> software counter value should be. So instead provide a new function
>>>>> drm_vblank_no_hw_counter() for drivers that don't have a real hw
>>>>> counter. The new function simply returns 0, which is about the only
>>>>> thing it can do.
>>>>
>>>> Shouldn't we instead just make the get_vblank_counter hook optional?
>>>
>>> Perhaps. But maybe this way would encourage people to go look for a
>>> hw frame counter in their hardware?
>>>
>>>> -Daniel
>>>>
>>>>>
>>>>> Cc: Vincent Abriou <vincent.abriou at st.com>
>>>>> Cc: Thierry Reding <treding at nvidia.com>
>>>>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>>>> ---
>>>>>    drivers/gpu/drm/armada/armada_drv.c          |  2 +-
>>>>>    drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c |  2 +-
>>>>>    drivers/gpu/drm/drm_irq.c                    | 17 +++++++++++++++++
>>>>>    drivers/gpu/drm/exynos/exynos_drm_drv.c      |  2 +-
>>>>>    drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c    |  2 +-
>>>>>    drivers/gpu/drm/imx/imx-drm-core.c           |  2 +-
>>
>> [..]
>>
>>>>> --- a/drivers/gpu/drm/drm_irq.c
>>>>> +++ b/drivers/gpu/drm/drm_irq.c
>>>>> @@ -1797,3 +1797,20 @@ bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
>>>>>       return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
>>>>>    }
>>>>>    EXPORT_SYMBOL(drm_crtc_handle_vblank);
>>>>> +
>>>>> +/**
>>>>> + * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
>>>>> + * @dev: DRM device
>>>>> + * @pipe: CRTC for which to read the counter
>>>>> + *
>>>>> + * Drivers can plug this into the .get_vblank_counter() function if
>>>>> + * there is no useable hardware frame counter available.
>>>>> + *
>>>>> + * Returns:
>>>>> + * 0
>>>>> + */
>>>>> +u32 drm_vblank_no_hw_counter(struct drm_device *dev, int pipe)
>>
>> warning when building the kernel:
>> int pipe => unsigned int pipe
>
> Where exactly? The function pointer signature still has a signed int
> here, and I was too lazy to go on a rampage to change all the remaining
> signed ints to unsigned for the vblank driver hooks.
>

I made the comment on the wrong patch. Sorry for that. It concern 
"[PATCH 2/2] drm: s/int pipe/unsigned int pipe/"

Vincent