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From: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
To: davej@codemonkey.org.uk
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>,
	andreas.herrmann3@amd.com, linux-kernel@vger.kernel.org,
	cpufreq@vger.kernel.org, mark.langsdorf@amd.com, trenn@suse.de
Subject: [PATCH 0/2] powernow-k8: fix incorrect value reported in cpuinfo_cur_freq
Date: Thu, 11 Jun 2009 15:26:43 +0000 (UTC)	[thread overview]
Message-ID: <20090611152558.8510.75249.sendpatchset@linux-fd7s.americas.hpqcorp.net> (raw)

The "cpuinfo_cur_freq" value reported in /sys is incorrect.

For example, on a 1P quad-core AMD platform (cores: 0,1,2,3) if you want the
"cpuinfo_cur_freq" for core2, you will actually get the value for core0. The
bug is apparent when all the cores are not at the same frequency.

Prior to 2.6.27.8, "cpuinfo_cur_freq" used to return the correct value because
query_current_values_with_pending_wait() obtained the P-state for core2 from
HW, and overwrote the "currpstate" for core0 with it.

However, that got broken with the commit:
a266d9f1253a38ec2d5655ebcd6846298b0554f4

This patch fixes the regression by:
- special-casing the AMD erratum 311 (discussed in the above commit) to AMD
Family 11h processors only
- cleaning up the way powernowk8_get() obtains the per-CPU data

 arch/x86/kernel/cpu/cpufreq/powernow-k8.c |   31 +++++++++++-----------------
 1 files changed, 12 insertions(+), 19 deletions(-)

Thanks,
- naga -



             reply	other threads:[~2009-06-11 15:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-11 15:26 Naga Chumbalkar [this message]
2009-06-11 15:26 ` [PATCH 1/2] powernow-k8: read P-state from HW Naga Chumbalkar
2009-06-11 15:26 ` [PATCH 2/2] powernow-k8: get drv data for correct CPU Naga Chumbalkar

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