From: Thierry Reding <thierry.reding@gmail.com>
To: Emil Velikov <emil.l.velikov@gmail.com>,
Vinay Simha BN <simhavcs@gmail.com>,
open list <linux-kernel@vger.kernel.org>,
"open list:DRM PANEL DRIVERS" <dri-devel@lists.freedesktop.org>,
Archit Taneja <archit.taneja@gmail.com>
Subject: Re: [PATCH v5 2/2] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel
Date: Tue, 12 Jul 2016 12:59:22 +0200 [thread overview]
Message-ID: <20160712105922.GA15685@ulmo.ba.sec> (raw)
In-Reply-To: <20160712103402.GA23520@phenom.ffwll.local>
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On Tue, Jul 12, 2016 at 12:34:02PM +0200, Daniel Vetter wrote:
> On Mon, Jul 11, 2016 at 02:29:37PM +0200, Thierry Reding wrote:
> > On Thu, Jun 16, 2016 at 06:02:53PM +0100, Emil Velikov wrote:
> > > On 16 June 2016 at 04:00, Vinay Simha BN <simhavcs@gmail.com> wrote:
> > [...]
> > > > +static int jdi_panel_disable(struct drm_panel *panel)
> > > > +{
> > > > + struct jdi_panel *jdi = to_jdi_panel(panel);
> > > > +
> > > > + if (!jdi->enabled)
> > > > + return 0;
> > > > +
> > > Thinking out loud:
> > >
> > > Thierry,
> > > Shouldn't we fold 'enabled' and 'prepared' in struct drm_panel and
> > > tweak the helpers respectively ? Is there any specific reason for
> > > keeping these in the drivers ?
> >
> > Yes, I think that would make sense eventually. It's clearly a recurring
> > pattern. Ideally nothing would be calling these functions more than once
> > and thereby making the checks unnecessary. In practice that may mean
> > that we need to put the variables and checks into the drm/panel core
> > because display drivers (as opposed to a sane core implementation) call
> > these. I suppose we could encourage proper usage by adding a couple of
> > WARNs here and there if expectations aren't met.
> >
> > I don't think doing this is terribly urgent because it's easy to rip out
> > of drivers once the drm/panel core supports it. And it's something that
> > we could even leave within drivers when the core supports it, so trivial
> > to remove one by one after the core patches have landed.
>
> As long as we have non-atomic drm drivers using this multiple
> enable/disable calls can happen. Atomic drivers should screw this up
> (ignoring a few misguided ones that mix atomic and legacy helpers in bad
> ways, but those are getting fixed).
>
> I think a good plan would be:
> 1. Move this tracking into drm panel helpers, ditch it from all drivers.
> 2. Add WARN_ON for multiple enables/disables, but only for DRIVER_ATOMIC.
>
> Makes sure we can remove this boilerplate, makes sure that atomic drivers
> are consistent, leaves existing drivers unharmed.
Yeah, that sounds like a reasonable plan.
Thierry
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prev parent reply other threads:[~2016-07-12 10:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 3:00 [PATCH v2 1/2] drm/dsi: Implement dcs set/get display brightness Vinay Simha BN
2016-06-16 3:00 ` [PATCH v5 2/2] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel Vinay Simha BN
2016-06-16 17:02 ` Emil Velikov
2016-07-11 12:29 ` Thierry Reding
2016-07-12 10:34 ` Daniel Vetter
2016-07-12 10:59 ` Thierry Reding [this message]
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