OMAP baseline test results for v3.7-rc1
Paul Walmsley
paul at pwsan.com
Tue Oct 30 09:17:22 EDT 2012
On Tue, 30 Oct 2012, Felipe Balbi wrote:
> On Tue, Oct 30, 2012 at 12:50:52PM +0000, Paul Walmsley wrote:
> > certainly PM-idle related, given that the problem goes away by reverting
> > Jean's commit 3db11feffc1ad2ab9dea27789e6b5b3032827adc "ARM: OMAP: convert
> > I2C driver to PM QoS for MPU latency constraints".
> >
> > The problem is consistent and easy to reproduce here.
>
> I don't doubt that :-) What I think, however, is that PM QoS just made
> the problem a bit easier to trigger for whatever reason. Maybe because
> pm qos defers constraint updates, or something similar ?
Based on a very quick look, I'd say the original patch 3db11fe is broken.
I don't see how it can ensure that its PM_QOS_CPU_DMA_LATENCY request is
honored when CONFIG_CPU_IDLE=n. CONFIG_CPU_IDLE=n is the default for
omap2plus_defconfig.
- Paul
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