* [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode
@ 2015-12-03 8:55 Philipp Zabel
2015-12-03 9:50 ` Daniel Vetter
0 siblings, 1 reply; 5+ messages in thread
From: Philipp Zabel @ 2015-12-03 8:55 UTC (permalink / raw)
To: David Airlie; +Cc: kernel, dri-devel
Use drm_mode_vrefresh to update the vrefresh field after changing the
modes' timings and flags.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
drivers/gpu/drm/drm_modes.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index cd74a09..b624be8 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -611,6 +611,8 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
dmode->flags |= DRM_MODE_FLAG_DBLCLK;
+ dmode->vrefresh = 0;
+ dmode->vrefresh = drm_mode_vrefresh(dmode);
drm_mode_set_name(dmode);
}
EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
--
2.6.2
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode
2015-12-03 8:55 [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode Philipp Zabel
@ 2015-12-03 9:50 ` Daniel Vetter
2015-12-03 10:22 ` Thierry Reding
0 siblings, 1 reply; 5+ messages in thread
From: Daniel Vetter @ 2015-12-03 9:50 UTC (permalink / raw)
To: Philipp Zabel; +Cc: dri-devel, kernel
On Thu, Dec 03, 2015 at 09:55:44AM +0100, Philipp Zabel wrote:
> Use drm_mode_vrefresh to update the vrefresh field after changing the
> modes' timings and flags.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> drivers/gpu/drm/drm_modes.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index cd74a09..b624be8 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -611,6 +611,8 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
> dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
> if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
> dmode->flags |= DRM_MODE_FLAG_DBLCLK;
> + dmode->vrefresh = 0;
Rendundant. Or I'm blind.
-Daniel
> + dmode->vrefresh = drm_mode_vrefresh(dmode);
> drm_mode_set_name(dmode);
> }
> EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
> --
> 2.6.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode
2015-12-03 9:50 ` Daniel Vetter
@ 2015-12-03 10:22 ` Thierry Reding
2015-12-03 11:09 ` Philipp Zabel
0 siblings, 1 reply; 5+ messages in thread
From: Thierry Reding @ 2015-12-03 10:22 UTC (permalink / raw)
To: Daniel Vetter; +Cc: kernel, dri-devel
[-- Attachment #1.1: Type: text/plain, Size: 1276 bytes --]
On Thu, Dec 03, 2015 at 10:50:07AM +0100, Daniel Vetter wrote:
> On Thu, Dec 03, 2015 at 09:55:44AM +0100, Philipp Zabel wrote:
> > Use drm_mode_vrefresh to update the vrefresh field after changing the
> > modes' timings and flags.
> >
> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > ---
> > drivers/gpu/drm/drm_modes.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> > index cd74a09..b624be8 100644
> > --- a/drivers/gpu/drm/drm_modes.c
> > +++ b/drivers/gpu/drm/drm_modes.c
> > @@ -611,6 +611,8 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
> > dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
> > if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
> > dmode->flags |= DRM_MODE_FLAG_DBLCLK;
> > + dmode->vrefresh = 0;
>
> Rendundant. Or I'm blind.
Unfortunately it isn't. drm_mode_vrefresh() is somewhat odd in that
it'll return the existing mode->vrefresh if it is > 0. I'm thinking that
perhaps it'd be useful to factor out the computation code into a
separate function, say drm_mode_calc_vrefresh(), and use that where you
really want to compute the value and at the same time use it to simplify
drm_mode_vrefresh() as well.
Thierry
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode
2015-12-03 10:22 ` Thierry Reding
@ 2015-12-03 11:09 ` Philipp Zabel
2015-12-04 7:57 ` Daniel Vetter
0 siblings, 1 reply; 5+ messages in thread
From: Philipp Zabel @ 2015-12-03 11:09 UTC (permalink / raw)
To: Thierry Reding; +Cc: kernel, dri-devel
Am Donnerstag, den 03.12.2015, 11:22 +0100 schrieb Thierry Reding:
> On Thu, Dec 03, 2015 at 10:50:07AM +0100, Daniel Vetter wrote:
> > On Thu, Dec 03, 2015 at 09:55:44AM +0100, Philipp Zabel wrote:
> > > Use drm_mode_vrefresh to update the vrefresh field after changing the
> > > modes' timings and flags.
> > >
> > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > > ---
> > > drivers/gpu/drm/drm_modes.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> > > index cd74a09..b624be8 100644
> > > --- a/drivers/gpu/drm/drm_modes.c
> > > +++ b/drivers/gpu/drm/drm_modes.c
> > > @@ -611,6 +611,8 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
> > > dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
> > > if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
> > > dmode->flags |= DRM_MODE_FLAG_DBLCLK;
> > > + dmode->vrefresh = 0;
> >
> > Rendundant. Or I'm blind.
>
> Unfortunately it isn't. drm_mode_vrefresh() is somewhat odd in that
> it'll return the existing mode->vrefresh if it is > 0. I'm thinking that
> perhaps it'd be useful to factor out the computation code into a
> separate function, say drm_mode_calc_vrefresh(), and use that where you
> really want to compute the value and at the same time use it to simplify
> drm_mode_vrefresh() as well.
I don't understand the intention behind the drm_mode_vrefresh (and
drm_mode_hsync) functions, but replacing all instances of
mode->vrefresh = drm_mode_vrefresh(mode)
with something that always calculates the vrefresh sounds like a good
idea to me.
regards
Philipp
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode
2015-12-03 11:09 ` Philipp Zabel
@ 2015-12-04 7:57 ` Daniel Vetter
0 siblings, 0 replies; 5+ messages in thread
From: Daniel Vetter @ 2015-12-04 7:57 UTC (permalink / raw)
To: Philipp Zabel; +Cc: kernel, dri-devel
On Thu, Dec 03, 2015 at 12:09:24PM +0100, Philipp Zabel wrote:
> Am Donnerstag, den 03.12.2015, 11:22 +0100 schrieb Thierry Reding:
> > On Thu, Dec 03, 2015 at 10:50:07AM +0100, Daniel Vetter wrote:
> > > On Thu, Dec 03, 2015 at 09:55:44AM +0100, Philipp Zabel wrote:
> > > > Use drm_mode_vrefresh to update the vrefresh field after changing the
> > > > modes' timings and flags.
> > > >
> > > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > > > ---
> > > > drivers/gpu/drm/drm_modes.c | 2 ++
> > > > 1 file changed, 2 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> > > > index cd74a09..b624be8 100644
> > > > --- a/drivers/gpu/drm/drm_modes.c
> > > > +++ b/drivers/gpu/drm/drm_modes.c
> > > > @@ -611,6 +611,8 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
> > > > dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
> > > > if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
> > > > dmode->flags |= DRM_MODE_FLAG_DBLCLK;
> > > > + dmode->vrefresh = 0;
> > >
> > > Rendundant. Or I'm blind.
> >
> > Unfortunately it isn't. drm_mode_vrefresh() is somewhat odd in that
> > it'll return the existing mode->vrefresh if it is > 0. I'm thinking that
> > perhaps it'd be useful to factor out the computation code into a
> > separate function, say drm_mode_calc_vrefresh(), and use that where you
> > really want to compute the value and at the same time use it to simplify
> > drm_mode_vrefresh() as well.
>
> I don't understand the intention behind the drm_mode_vrefresh (and
> drm_mode_hsync) functions, but replacing all instances of
>
> mode->vrefresh = drm_mode_vrefresh(mode)
>
> with something that always calculates the vrefresh sounds like a good
> idea to me.
Premature micro-optimization to avoid recomputing hrefresh/vrefresh all
the time I think. I'd drop this, and then redo your patch on top to also
drop the = 0 assignment.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-12-04 7:57 UTC | newest]
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2015-12-03 8:55 [PATCH] drm_modes: calculate nominal vrefresh in drm_display_mode_from_videomode Philipp Zabel
2015-12-03 9:50 ` Daniel Vetter
2015-12-03 10:22 ` Thierry Reding
2015-12-03 11:09 ` Philipp Zabel
2015-12-04 7:57 ` Daniel Vetter
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