From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: NeilBrown <neilb@suse.de>
Cc: Paul Walmsley <paul@pwsan.com>, Joe Woodward <jw@terrafix.co.uk>,
khilman@ti.com, t-kristo@ti.com, govindraj.r@ti.com,
linux-omap@vger.kernel.org
Subject: Re: DSS2/PM on 3.2 broken?
Date: Wed, 18 Jan 2012 09:13:59 +0200 [thread overview]
Message-ID: <1326870839.1954.23.camel@deskari> (raw)
In-Reply-To: <20120113222045.37f9b4ec@notabene.brown>
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On Fri, 2012-01-13 at 22:20 +1100, NeilBrown wrote:
> Having CPUIDLE makes the DSS2 problem worse: lots of
>
> [ 21.085113] omapdss DISPC error: SYNC_LOST on channel lcd,
> restarting the output with video overlays disabled
>
> messages whenever the CPU isn't busy.
I'm not sure if it is the case here, but DSS has restrictions about the
max DSS clocks on different OPPs. For example, on OMAP4430 LCD clock
maximum is 186MHz at OPP100, and 93MHz at OPP50. So it's a quite big
drop, causing problems with all but the rather small displays.
And the DSS driver doesn't have any support to handle this at the
moment, as there isn't support in the PM framework to do this. I think
the only way to handle this at the moment is for the DSS driver to set
an arbitrarily high constraint on, say, mem throughput, and hope that it
keeps the OMAP in the required OPP.
Tomi
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next prev parent reply other threads:[~2012-01-18 7:14 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-09 12:46 DSS2/PM on 3.2 broken? Joe Woodward
2012-01-09 21:08 ` NeilBrown
2012-01-10 9:58 ` Joe Woodward
2012-01-11 13:43 ` Paul Walmsley
2012-01-11 14:22 ` Archit
2012-01-11 15:15 ` Joe Woodward
2012-01-11 15:52 ` Archit
2012-01-11 16:13 ` Joe Woodward
2012-01-11 16:54 ` Archit
2012-01-12 9:28 ` Tomi Valkeinen
2012-01-12 9:30 ` Tomi Valkeinen
2012-01-12 9:51 ` Tomi Valkeinen
2012-01-11 22:59 ` NeilBrown
2012-01-13 10:05 ` Paul Walmsley
2012-01-13 11:20 ` NeilBrown
2012-01-13 11:31 ` Paul Walmsley
2012-01-13 23:09 ` NeilBrown
2012-01-13 23:35 ` Paul Walmsley
2012-01-17 21:24 ` NeilBrown
2012-01-22 0:07 ` Paul Walmsley
2012-01-22 11:30 ` NeilBrown
2012-01-24 10:37 ` OMAP HDQ: was " NeilBrown
2012-01-26 14:19 ` Paul Walmsley
2012-01-27 22:35 ` NeilBrown
2012-01-27 22:58 ` Paul Walmsley
2012-01-28 0:40 ` NeilBrown
2012-01-28 6:02 ` Paul Walmsley
2012-02-01 7:51 ` NeilBrown
2012-02-01 18:36 ` Paul Walmsley
2012-01-18 7:13 ` Tomi Valkeinen [this message]
2012-01-18 11:15 ` NeilBrown
2012-01-18 11:42 ` Tomi Valkeinen
2012-01-18 20:30 ` NeilBrown
2012-01-19 10:17 ` Joe Woodward
2012-01-19 10:40 ` Tomi Valkeinen
2012-01-19 11:29 ` Joe Woodward
2012-01-19 11:36 ` Tomi Valkeinen
2012-01-19 12:21 ` Joe Woodward
2012-01-19 14:52 ` Tomi Valkeinen
2012-01-19 19:37 ` Kevin Hilman
2012-01-19 21:05 ` NeilBrown
2012-01-20 0:22 ` Kevin Hilman
2012-01-21 12:12 ` NeilBrown
2012-01-23 22:11 ` Kevin Hilman
2012-01-25 0:32 ` NeilBrown
2012-01-13 11:34 ` Govindraj
2012-01-13 13:23 ` Paul Walmsley
2012-01-13 19:21 ` Kevin Hilman
2012-01-13 22:37 ` Kevin Hilman
2012-01-13 23:06 ` Paul Walmsley
2012-01-13 23:34 ` Paul Walmsley
2012-01-14 1:17 ` NeilBrown
2012-01-14 1:28 ` Paul Walmsley
2012-01-13 23:39 ` Paul Walmsley
2012-01-13 11:19 ` Paul Walmsley
2012-01-11 13:32 ` Paul Walmsley
2012-01-12 16:42 ` Tomi Valkeinen
2012-01-12 22:40 ` Kevin Hilman
2012-01-13 5:29 ` Tomi Valkeinen
2012-01-13 19:30 ` Kevin Hilman
2012-01-16 11:11 ` Tomi Valkeinen
2012-01-19 19:24 ` Kevin Hilman
2012-01-20 7:16 ` Tomi Valkeinen
2012-01-20 18:06 ` Kevin Hilman
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