Re: [PATCH] drm: hdlcd: Update PM code to save/restore console.

[Noralf TrÃnnes]

Den 19.06.2017 15.17, skrev Liviu Dudau:
> On Fri, Jun 16, 2017 at 06:58:36PM +0200, Noralf TrÃnnes wrote:
> > Den 16.06.2017 15.53, skrev Liviu Dudau:
> > > Update the PM code to suspend/resume the fbdev_cma console.
> > >
> > > Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> > > ---
> > >    drivers/gpu/drm/arm/hdlcd_drv.c | 11 ++++++++++-
> > >    1 file changed, 10 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
> > > index d3da87fbd85a..89cd408cde6f 100644
> > > --- a/drivers/gpu/drm/arm/hdlcd_drv.c
> > > +++ b/drivers/gpu/drm/arm/hdlcd_drv.c
> > > @@ -13,6 +13,7 @@
> > >    #include <linux/spinlock.h>
> > >    #include <linux/clk.h>
> > >    #include <linux/component.h>
> > > +#include <linux/console.h>
> > >    #include <linux/list.h>
> > >    #include <linux/of_graph.h>
> > >    #include <linux/of_reserved_mem.h>
> > > @@ -435,9 +436,15 @@ static int __maybe_unused hdlcd_pm_suspend(struct device *dev)
> > >    		return 0;
> > >    	drm_kms_helper_poll_disable(drm);
> > > +	console_lock();
> > > +	drm_fbdev_cma_set_suspend(hdlcd->fbdev, 1);
> > > +	console_unlock();
> > You can use drm_fbdev_cma_set_suspend_unlocked() instead, it takes the
> > lock for you and can speed up resume if the lock is contented.
> Hi Noralf,
>
> Thanks for pointing out the helpful function. As you look to be the author of it,
> any reason why the signature of the function doesn't match the drm_fb_helper_ one
> being called through? (I'm talking about int vs bool for the state/suspend arguments).

I don't remember, but probably to match drm_fbdev_cma_set_suspend()
which uses int. drm_fb_helper_set_suspend*() uses bool, but calls
into fb_set_suspend() which uses int, but as a boolean.

Noralf.
> Best regards,
> Liviu
>
> > Noralf.
> >
> >
> > >    	hdlcd->state = drm_atomic_helper_suspend(drm);
> > >    	if (IS_ERR(hdlcd->state)) {
> > > +		console_lock();
> > > +		drm_fbdev_cma_set_suspend(hdlcd->fbdev, 0);
> > > +		console_unlock();
> > >    		drm_kms_helper_poll_enable(drm);
> > >    		return PTR_ERR(hdlcd->state);
> > >    	}
> > > @@ -454,8 +461,10 @@ static int __maybe_unused hdlcd_pm_resume(struct device *dev)
> > >    		return 0;
> > >    	drm_atomic_helper_resume(drm, hdlcd->state);
> > > +	console_lock();
> > > +	drm_fbdev_cma_set_suspend(hdlcd->fbdev, 0);
> > > +	console_unlock();
> > >    	drm_kms_helper_poll_enable(drm);
> > > -	pm_runtime_set_active(dev);
> > >    	return 0;
> > >    }