diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2012-11-15 17:27:43 +0100 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2012-11-15 17:27:43 +0100 |
| commit | 12480c2e53d355223cf6884ed1f56e6ac9b7c21f (patch) | |
| tree | c244c5b4f265dc38f7658fbe5714ba2c402aef28 /arch/x86/kernel/cpu/perf_event.c | |
| parent | 6c8e94a57c30e31d0807f038b4f98b659fd67776 (diff) | |
| parent | 936407358759adb302df93ab61fa68141897270c (diff) | |
Merge tag 'omap-for-v3.8/fixes-non-critical-v4-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/fixes-non-critical
From Tony Lindgren <tony@atomide.com>:
Non critical omap fixes that were not considered urgent
for the -rc cycle.
* tag 'omap-for-v3.8/fixes-non-critical-v4-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (645 commits)
ARM: OMAP4: PM: fix errata handling when CONFIG_PM=n
ARM: OMAP4: retrigger localtimers after re-enabling gic
ARM: OMAP4460: Workaround for ROM bug because of CA9 r2pX GIC control register change.
ARM: OMAP4: PM: add errata support
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 3373f84d139..4a3374e61a9 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -208,12 +208,14 @@ static bool check_hw_exists(void) } /* - * Now write a value and read it back to see if it matches, - * this is needed to detect certain hardware emulators (qemu/kvm) - * that don't trap on the MSR access and always return 0s. + * Read the current value, change it and read it back to see if it + * matches, this is needed to detect certain hardware emulators + * (qemu/kvm) that don't trap on the MSR access and always return 0s. */ - val = 0xabcdUL; reg = x86_pmu_event_addr(0); + if (rdmsrl_safe(reg, &val)) + goto msr_fail; + val ^= 0xffffUL; ret = wrmsrl_safe(reg, val); ret |= rdmsrl_safe(reg, &val_new); if (ret || val != val_new) |