Messages in this thread | | | Date | Thu, 4 Nov 2021 09:30:19 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] cpufreq: intel_pstate: Fix unchecked MSR 0x773 access |
| |
On Wed, 3 Nov 2021 22:19:25 -0700 Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote:
> It is possible that on some platforms HWP interrupts are disabled. In > that case accessing MSR 0x773 will result in warning. > > So check X86_FEATURE_HWP_NOTIFY feature to access MSR 0x773. The other > places in code where this MSR is accessed, already checks this feature > except during disable path called during cpufreq offline and suspend > callbacks. > > Fixes: 57577c996d73 ("cpufreq: intel_pstate: Process HWP Guaranteed change notification") > Reported-by: Steven Rostedt <rostedt@goodmis.org>
I added this patch on top of the above commit and I verified that the issue goes away. And just to confirm, I removed the patch, and the issue reappeared.
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > --- > drivers/cpufreq/intel_pstate.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index 349ddbaef796..1e6898dc76b6 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -1620,6 +1620,9 @@ static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata) > { > unsigned long flags; > > + if (!boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) > + return; > + > /* wrmsrl_on_cpu has to be outside spinlock as this can result in IPC */ > wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00); >
| |