From: Richard Purdie <rpurdie@rpsys.net>
To: Zhang Rui <rui.zhang@intel.com>
Cc: linux-acpi <linux-acpi@vger.kernel.org>, Len Brown <lenb@kernel.org>
Subject: Re: [PATCH 1/2] video: always update the brightness when poking "brightness"
Date: Tue, 30 Dec 2008 10:34:10 +0000 [thread overview]
Message-ID: <1230633250.5328.8.camel@dax.rpnet.com> (raw)
In-Reply-To: <1230088058.562.219.camel@rzhang-dt>
On Wed, 2008-12-24 at 11:07 +0800, Zhang Rui wrote:
> bd->props.brightness is a cached value.
> the current code has some potential problems when poking the
> backlight I/F.
>
> For example,
> 1. set the brightness level to 5 via sysfs I/F
> 2. set the backlight to another level via the procfs,
> 3. setting it back to 5 doesn't work because bd->props.brightness
> is still 5.
>
> http://bugzilla.kernel.org/show_bug.cgi?id=12249
The root of the problem here is that there are two interfaces
controlling the same piece of hardware. Personally, I'd like to see the
proc interfaces to backlights depreacated but we do need to make them
work I guess. The real bug looks like the proc interface should update
props.brightness for that hardware...
Cheers,
Richard
--
Richard Purdie
Intel Open Source Technology Centre
next prev parent reply other threads:[~2008-12-30 11:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-24 3:07 [PATCH 1/2] video: always update the brightness when poking "brightness" Zhang Rui
2008-12-30 10:34 ` Richard Purdie [this message]
2008-12-31 1:22 ` Zhao Yakui
2008-12-31 1:21 ` Matthew Garrett
2008-12-31 1:43 ` Zhang Rui
2008-12-31 2:01 ` Matthew Garrett
2008-12-31 2:58 ` Zhang Rui
2008-12-31 3:11 ` Zhang Rui
2008-12-31 3:24 ` Matthew Garrett
2008-12-31 3:14 ` Matthew Garrett
2008-12-31 13:41 ` Matthew Garrett
2008-12-31 14:16 ` Richard Purdie
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