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27 March 2024, 02:37:15 UTC
Revision 0213df74315bbab9ccaa73146f3e11972ea6de46 authored by Dave Jones on 21 October 2005, 21:21:03 UTC, committed by Linus Torvalds on 21 October 2005, 21:28:58 UTC 
[PATCH] cpufreq: fix pending powernow timer stuck condition
 
AMD recently discovered that on some hardware, there is a race condition
possible when a C-state change request goes onto the bus at the same
time as a P-state change request.

Both requests happen, but the southbridge hardware only acknowledges the
C-state change.  The PowerNow! driver is then stuck in a loop, waiting
for the P-state change acknowledgement.  The driver eventually times
out, but can no longer perform P-state changes.

It turns out the solution is to resend the P-state change, which the
southbridge will acknowledge normally.

Thanks to Johannes Winkelmann for reporting this and testing the fix.

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 3078fcc
History
Tip revision: 0213df74315bbab9ccaa73146f3e11972ea6de46 authored by Dave Jones on 21 October 2005, 21:21:03 UTC
[PATCH] cpufreq: fix pending powernow timer stuck condition
Tip revision: 0213df7
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