From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Cc: jani.nikula@intel.com, david.woodhouse@intel.com
Subject: Re: [PATCH] drm/i915: do not expose a dysfunctional backlight interface to userspace
Date: Mon, 03 Sep 2012 18:51:31 +0100 [thread overview]
Message-ID: <051c15$46gcp3@AZSMGA002.ch.intel.com> (raw)
In-Reply-To: <1346678712-30513-1-git-send-email-jani.nikula@intel.com>
On Mon, 3 Sep 2012 16:25:12 +0300, Jani Nikula <jani.nikula@intel.com> wrote:
> Previously intel_panel_setup_backlight() would create a sysfs backlight
> interface with max brightness of 1 if it was unable to figure out the max
> backlight brightness. This rendered the backlight interface useless.
>
> Do not create a dysfunctional backlight interface to begin with.
>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>
> See https://bugzilla.redhat.com/show_bug.cgi?id=752595
>
> There's still a bug somewhere in the userspace as well; it should always
> prefer the platform backlight interface over the raw one. This patch might
> have the effect of hiding that particular userspace issue, but we shouldn't
> be exporting a backlight interface that's useless no matter what.
It was fixed. UXA uses a hardcoded set of preferred platform drivers,
SNA looks at all the backlights under /sys/class/backlight and sorts
them by type. We still have the issue of multi-panel or just multiple
backlight interfaces and choosing the wrong one randomly. libbacklight's
idea was to expose some more details through the kernel to be able to
link device + connector to a particular backlight interface. However,
userspace has the Option "Backlight" for fine tuning.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2012-09-03 17:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 13:25 [PATCH] drm/i915: do not expose a dysfunctional backlight interface to userspace Jani Nikula
2012-09-03 17:51 ` Chris Wilson [this message]
2012-09-03 18:42 ` Daniel Vetter
[not found] ` <1346698833.7326.0.camel@shinybook.infradead.org>
2012-09-04 7:39 ` Jani Nikula
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