OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[CPUFREQ] powernow-k8: Limit Pstate transition latency check 

The Pstate transition latency check was added for broken F10h BIOSen
which wrongly contain a value of 0 for transition and bus master
latency. Fam11h and later, however, (will) have similar transition
latency so extend that behavior for them too.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Borislav Petkov 2010-07-08 17:55:30 +02:00 committed by Dave Jones
parent 179ee43465
commit 3581ced3b6
1 changed files with 5 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/x86/kernel/cpu/cpufreq/powernow-k8.c
View File

@ -1023,13 +1023,12 @@ static int get_transition_latency(struct powernow_k8_data *data)
}
if (max_latency == 0) {
/*
* Fam 11h always returns 0 as transition latency.
* This is intended and means "very fast". While cpufreq core
* and governors currently can handle that gracefully, better
* set it to 1 to avoid problems in the future.
* For all others it's a BIOS bug.
* Fam 11h and later may return 0 as transition latency. This
* is intended and means "very fast". While cpufreq core and
* governors currently can handle that gracefully, better set it
* to 1 to avoid problems in the future.
*/
if (boot_cpu_data.x86 != 0x11)
if (boot_cpu_data.x86 < 0x11)
printk(KERN_ERR FW_WARN PFX "Invalid zero transition "
"latency\n");
max_latency = 1;