| Message ID | 1456441771-4961-1-git-send-email-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
On Thursday, February 25, 2016 03:09:31 PM Srinivas Pandruvada wrote: > Disable HWP Interrupt notification before enabling HWP. Since we don't > have HWP interrupt handling for possible performance interrupts, there > is not much use of enabling HWP interrupts. > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> The patch is fine, but are there any known systems where it fixes any functional issues just for the record? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2016-02-26 at 00:18 +0100, Rafael J. Wysocki wrote: > On Thursday, February 25, 2016 03:09:31 PM Srinivas Pandruvada wrote: > > Disable HWP Interrupt notification before enabling HWP. Since we > > don't > > have HWP interrupt handling for possible performance interrupts, > > there > > is not much use of enabling HWP interrupts. > > > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel > > .com> > > The patch is fine, but are there any known systems where it fixes any > functional issues just for the record? We don't know whether it fixes any functional issue. But it was set on some system on boot. I worry that this may cause flooding of interrupt during boot if there are some thermal issues. Thanks, Srinivas > > Rafael > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday, February 25, 2016 03:20:42 PM Srinivas Pandruvada wrote: > On Fri, 2016-02-26 at 00:18 +0100, Rafael J. Wysocki wrote: > > On Thursday, February 25, 2016 03:09:31 PM Srinivas Pandruvada wrote: > > > Disable HWP Interrupt notification before enabling HWP. Since we > > > don't > > > have HWP interrupt handling for possible performance interrupts, > > > there > > > is not much use of enabling HWP interrupts. > > > > > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel > > > .com> > > > > The patch is fine, but are there any known systems where it fixes any > > functional issues just for the record? > > We don't know whether it fixes any functional issue. OK > But it was set on some system on boot. I worry that this may cause flooding > of interrupt during boot if there are some thermal issues. It obviously may lead to problems, which is why the patch is needed. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday, February 26, 2016 02:28:00 AM Rafael J. Wysocki wrote: > On Thursday, February 25, 2016 03:20:42 PM Srinivas Pandruvada wrote: > > On Fri, 2016-02-26 at 00:18 +0100, Rafael J. Wysocki wrote: > > > On Thursday, February 25, 2016 03:09:31 PM Srinivas Pandruvada wrote: > > > > Disable HWP Interrupt notification before enabling HWP. Since we > > > > don't > > > > have HWP interrupt handling for possible performance interrupts, > > > > there > > > > is not much use of enabling HWP interrupts. > > > > > > > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel > > > > .com> > > > > > > The patch is fine, but are there any known systems where it fixes any > > > functional issues just for the record? > > > > We don't know whether it fixes any functional issue. > > OK > > > But it was set on some system on boot. I worry that this may cause flooding > > of interrupt during boot if there are some thermal issues. > > It obviously may lead to problems, which is why the patch is needed. I've queued it up for 4.6, thanks! Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index f4d85c2..80ea548 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -532,6 +532,9 @@ static void __init intel_pstate_sysfs_expose_params(void) static void intel_pstate_hwp_enable(struct cpudata *cpudata) { + /* First disable HWP notification interrupt as we don't process them */ + wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00); + wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1); }
Disable HWP Interrupt notification before enabling HWP. Since we don't have HWP interrupt handling for possible performance interrupts, there is not much use of enabling HWP interrupts. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> --- drivers/cpufreq/intel_pstate.c | 3 +++ 1 file changed, 3 insertions(+)