[Intel-gfx] [PATCH v2] drm/i915/fbdev: Enable late fbdev initial configuration

[Jani Nikula]

On Wed, 18 Apr 2018, José Roberto de Souza <jose.souza at intel.com> wrote:
> If the initial fbdev configuration(intel_fbdev_initial_config()) runs and
> there still no sink connected it will cause
> drm_fb_helper_initial_config() to return 0 as no error happened(but
> internally the return is -EAGAIN).
> Because no framebuffer was allocated, when a sink is connected
> intel_fbdev_output_poll_changed() will not execute
> drm_fb_helper_hotplug_event() that would trigger another try to do the
> initial fbdev configuration.
>
> So here allowing drm_fb_helper_hotplug_event() to be executed when there
> is not frambebuffer allocated and fbdev was not setup yet.
>
> This issue also happens when a MST DP sink is connected since boot, as
> the MST topology is discovered in parallel if intel_fbdev_initial_config()
> is executed before the first sink MST is discovered it will cause this
> same issue.
>
> This is a follow up patch of
> https://patchwork.freedesktop.org/patch/196089/

What does this mean? Is that patch a required dependency? What?

> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104158
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104425

People responded to v1, please ask them to test v2.

> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>
> Changes from v1:
> - not creating a dump framebuffer anymore, instead just allowing
> drm_fb_helper_hotplug_event() to execute when fbdev is not setup yet.

Please look at git log in drm, and observe how we include the changelog
in the commit message itself.

BR,
Jani.

>
>  drivers/gpu/drm/i915/intel_fbdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index 7d41d139341b..e9e02b58b7be 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -807,7 +807,7 @@ void intel_fbdev_output_poll_changed(struct drm_device *dev)
>  		return;
>  
>  	intel_fbdev_sync(ifbdev);
> -	if (ifbdev->vma)
> +	if (ifbdev->vma || ifbdev->helper.deferred_setup)
>  		drm_fb_helper_hotplug_event(&ifbdev->helper);
>  }

-- 
Jani Nikula, Intel Open Source Technology Center