linux-kernel - Re: [PATCH 1/2] drm/rockchip: vop use is

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Date:	Thu, 22 Jan 2015 14:27:27 +0100
From:	Daniel Vetter <daniel@...ll.ch>
To:	Mark yao <mark.yao@...k-chips.com>
Cc:	David Airlie <airlied@...ux.ie>, Rob Clark <robdclark@...il.com>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	Daniel Kurtz <djkurtz@...omium.org>,
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
	linux-rockchip@...ts.infradead.org
Subject: Re: [PATCH 1/2] drm/rockchip: vop use is_enabled instead of dpms mode

On Thu, Jan 22, 2015 at 04:56:09PM +0800, Mark yao wrote:
> On 2015年01月22日 15:33, Daniel Vetter wrote:
> >On Thu, Jan 22, 2015 at 03:05:32PM +0800, Mark Yao wrote:
> >>drm dpms have many power modes: ON,OFF,SUSPEND,STANDBY, etc.
> >>but vop only have enable/disable mode, maybe case such bug:
> >>  --> DRM_DPMS_ON: power on vop
> >>  --> DRM_DPMS_SUSPEND: power off vop
> >>  --> DRM_DPMS_OFF: already power off at SUSPEND, crash
> >>so use a bool val is more suitable.
> >>
> >>Signed-off-by: Mark Yao <mark.yao@...k-chips.com>
> >Long term I highly suggest you switch to atomic, since with atomic all the
> >legacy dpms modes are remapped to a simple on/off. Also the new atomic
> >helpers make sure that your backend isn't called multiple times, so you
> >can ditch all your is_enabled tracking with that.
> >-Daniel
> Hi Daniel
> is there some documents teach me how to switch to atomic easily?
> I found many other drivers which use atomic also remap dpms modes to simple
> on/off at its driver,
> and I don't know where atomic helper do the remapped, can you give me some
> suggestions?

The dpms remapping patches are still in-flight. But for the general atomic
conversion please look at

http://blog.ffwll.ch/2014/11/atomic-modeset-support-for-kms-drivers.html

If you want to look at an actual driver there's msm already merged, tegra
(conversion just posted) and exynos (iirc not yet published all, but
Gustavo should have a branch for you to look at somewhere).

Cheers, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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