[Intel-gfx] [PATCH v3 07/10] drm/exynos: Remove custom FB helper deferred setup

[Thierry Reding]

On Tue, Mar 21, 2017 at 12:13:26PM +0100, Andrzej Hajda wrote:
> On 21.03.2017 11:53, Thierry Reding wrote:
> > On Tue, Mar 21, 2017 at 11:42:21AM +0100, Andrzej Hajda wrote:
> >> On 21.03.2017 11:20, Daniel Vetter wrote:
> >>> On Tue, Mar 21, 2017 at 10:58:43AM +0100, Andrzej Hajda wrote:
> >>>> On 21.03.2017 09:13, Thierry Reding wrote:
> >>>>> From: Thierry Reding <treding at nvidia.com>
> >>>>>
> >>>>> The FB helper core now supports deferred setup, so the driver's custom
> >>>>> implementation can be removed.
> >>>>>
> >>>>> Signed-off-by: Thierry Reding <treding at nvidia.com>
> >>>>> ---
> >>>>>  drivers/gpu/drm/exynos/exynos_drm_drv.c   | 6 ++++--
> >>>>>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 2 --
> >>>>>  2 files changed, 4 insertions(+), 4 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> >>>>> index 09d3c4c3c858..c5a37dda8d1b 100644
> >>>>> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> >>>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> >>>>> @@ -399,8 +399,9 @@ static int exynos_drm_bind(struct device *dev)
> >>>>>  	/* init kms poll for handling hpd */
> >>>>>  	drm_kms_helper_poll_init(drm);
> >>>>>  
> >>>>> -	/* force connectors detection */
> >>>>> -	drm_helper_hpd_irq_event(drm);
> >>>>> +	ret = exynos_drm_fbdev_init(dev);
> >>>>> +	if (ret)
> >>>>> +		goto err_cleanup_poll;
> >>>> It should be rather:
> >>>>     ret = exynos_drm_fbdev_init(drm);
> >>>>
> >>>> Even with this change it does not work, I will try to track down the
> >>>> problem.
> >> The solution was to remove custom equivalent of
> >> drm_fb_helper_maybe_connected - exynos_drm_fbdev_is_anything_connected,
> >> it is called earlier and it was a part of custom deferred fbdev.
> > Cool, thanks for figuring that out. I can add that to this patch for v4.
> >
> >>> We might need the multi-stage fbdev setup here, i.e. init fbdev, run
> >>> hpd_irq_event() (I suspect that kicks all the connectors to start
> >>> probing), then initial_config for fbdev.
> >>>
> >>> Probably simplest way to achieve this is to keep the hpd_irq_event call,
> >>> but place it _after_ the fbdev_init.
> >>> -Daniel
> >> I wonder if it wouldn't be sufficient to check if there is anything
> >> connected, instead of checking if there is anything not-disconnected, in
> >> drm_fb_helper_maybe_connected.
> > My recollection is that this had been discussed when I first sent this
> > out. VGA outputs are somewhat of a special case in that you can't always
> > properly detect that it's connected or not. So effectively we need to
> > take into account the connector_status_unknown. There's also some more
> > information about this in the kerneldoc for enum drm_connector_status.
> 
> OK, I forgot about it and assumed that it is only used for initial state
> of connector.
> Returning to Daniel's proposition about hpd_irq_event(), it seems
> unnecessary then: before calling drm_fb_helper_maybe_connected
> drm_fb_helper_probe_connector_modes is called, which calls fill_modes
> callback which should perform connector probing anyway, am I right?

Yes, that matches my understanding of the call sequence.

Thierry
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