| From 1f858ef2fbabdc5e645644010a31a40c32e397c9 Mon Sep 17 00:00:00 2001 |
| From: Naga Chumbalkar <nagananda.chumbalkar@hp.com> |
| Date: Wed, 9 Mar 2011 14:02:49 +0000 |
| Subject: [CPUFREQ] pcc-cpufreq: don't load driver if get_freq fails during init. |
| |
| From: Naga Chumbalkar <nagananda.chumbalkar@hp.com> |
| |
| commit 1f858ef2fbabdc5e645644010a31a40c32e397c9 upstream. |
| |
| Return 0 on failure. This will cause the initialization of the driver |
| to fail and prevent the driver from loading if the BIOS cannot handle |
| the PCC interface command to "get frequency". Otherwise, the driver |
| will load and display a very high value like "4294967274" (which is |
| actually -EINVAL) for frequency: |
| |
| # cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq |
| 4294967274 |
| |
| Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> |
| Signed-off-by: Dave Jones <davej@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c |
| +++ b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c |
| @@ -195,7 +195,7 @@ static unsigned int pcc_get_freq(unsigne |
| cmd_incomplete: |
| iowrite16(0, &pcch_hdr->status); |
| spin_unlock(&pcc_lock); |
| - return -EINVAL; |
| + return 0; |
| } |
| |
| static int pcc_cpufreq_target(struct cpufreq_policy *policy, |
