[Intel-gfx] [PATCH 04/26] drm/fb-helper: Add fill_info() functions

[Noralf Trønnes]

Den 25.01.2019 09.48, skrev Daniel Vetter:
> On Thu, Jan 24, 2019 at 06:40:52PM +0100, Noralf Trønnes wrote:
>>
>>
>> Den 24.01.2019 17.58, skrev Daniel Vetter:
>>> The fbdev split between fix and var information is kinda
>>> pointless for drm drivers since everything is fixed: The fbdev
>>> emulation doesn't support changing modes at all.
>>>
>>> Create a new simplified helper and use it in the generic fbdev
>>> helper code. Follow-up patches will beef it up more and roll
>>> it out to all drivers.
>>>
>>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>>> ---
>>>  drivers/gpu/drm/drm_fb_helper.c | 27 +++++++++++++++++++++++++--
>>>  include/drm/drm_fb_helper.h     |  1 +
>>>  2 files changed, 26 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>>> index 5eaccd202f4f..34c4ed378796 100644
>>> --- a/drivers/gpu/drm/drm_fb_helper.c
>>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>>> @@ -2105,6 +2105,30 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
>>>  }
>>>  EXPORT_SYMBOL(drm_fb_helper_fill_var);
>>>  
>>> +/**
>>> + * drm_fb_helper_fill_info - initializes fbdev information
>>> + * @info: fbdev instance to set up
>>> + * @fb_helper: fb helper instance to use as template
>>> + *
>>> + *
>>> + * Sets up the variable and fixed fbdev metainformation from the given fb helper
>>> + * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
>>> + *
>>> + * Drivers should call this (or their equivalent setup code) from their
>>> + * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
>>> + * backing storage framebuffer.
>>> + */
>>> +void drm_fb_helper_fill_info(struct fb_info *info,
>>
>> No need to pass in fb_info it's available as fb_helper->fbdev. Set by
>> drm_fb_helper_alloc_fbi().
> 
> Uh, I get to edit all the patches. Still, thanks for pointing out.
> 
> I also realized that I've forgotten to add the dummy functiont for
> !CONFIG_FB, will fix that too.
> 
>>> +			     struct drm_fb_helper *fb_helper)
>>> +{
>>> +	struct drm_framebuffer *fb = fb_helper->fb;
>>> +
>>> +	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
>>> +	drm_fb_helper_fill_var(info, fb_helper, fb->width, fb->height);
>>
>> AFAIU fb->width/height can be different from sizes->fb_width/fb_height
>> when there's double/triple buffering. I belive you need to use the sizes
>> values here.
> 
> Yup they're bigger than the actual screen size, but so is sizes: For
> overallocting we adjust sizes before we call ->fb_probe, and the
> ->fb_probe callbacks in turn then call this helper. So I think it should
> be all equivalent. Agreed or do I miss something?

I did a test setting drm_fbdev_overalloc = 200:

[drm:drm_setup_crtcs] desired mode 320x240 set on crtc 33 (0,0)
[drm:drm_fb_helper_generic_probe] surface width(320), height(480) and
bpp(16)
[drm:drm_fb_helper_generic_probe] fb_width(320), fb_height(240)

sizes->surface_height != sizes->fb_height

sizes->surface_height is used to create the framebuffer -> fb->height.
My driver doesn't allow me to create such a big framebuffer so I didn't
see the actual fb->height value come out the other end, but I still
believe you need to use sizes->fb_height.

Noralf.

> -Daniel
> 
>>
>> Noralf.
>>
>>> +
>>> +}
>>> +EXPORT_SYMBOL(drm_fb_helper_fill_info);
>>> +
>>>  static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper,
>>>  						uint32_t maxX,
>>>  						uint32_t maxY)
>>> @@ -3163,8 +3187,7 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>>>  #endif
>>>  	strcpy(fbi->fix.id, "DRM emulated");
>>>  
>>> -	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
>>> -	drm_fb_helper_fill_var(fbi, fb_helper, sizes->fb_width, sizes->fb_height);
>>> +	drm_fb_helper_fill_info(fbi, fb_helper);
>>>  
>>>  	if (fb->funcs->dirty) {
>>>  		struct fb_ops *fbops;
>>> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
>>> index bb9acea61369..e8d92724f472 100644
>>> --- a/include/drm/drm_fb_helper.h
>>> +++ b/include/drm/drm_fb_helper.h
>>> @@ -292,6 +292,7 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
>>>  			    uint32_t fb_width, uint32_t fb_height);
>>>  void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
>>>  			    uint32_t depth);
>>> +void drm_fb_helper_fill_info(struct fb_info *info, struct drm_fb_helper *fb_helper);
>>>  
>>>  void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
>>>  
>>>
>