Re: intel_pstate_get_hwp_cap on wrong CPU

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2024-05-29 16:08:19 [-0700], srinivas pandruvada wrote:
> Hi Sebastian,
Hi,

> On Wed, 2024-05-29 at 17:57 +0200, Sebastian Andrzej Siewior wrote:
> > Hi,
> > 
> > this just popped up:
> > > [ 6538.614568] unchecked MSR access error: RDMSR from 0x771 at rIP:
> 
> Please check if the attached change fixes?

it should based on the callchain. Let me test it in a few…

Would you mind letting
  /sys/devices/system/cpu/intel_pstate/num_pstates

reporting something sane? Not 4294967285 but 0 for instance? Would that
make sense?

But
…
> From f85a83508ef029bceaf9192cb648d66f32b61d02 Mon Sep 17 00:00:00 2001
> From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> Date: Wed, 29 May 2024 15:30:49 -0700
> Subject: [PATCH] cpufreq: intel_pstate: Fix unchecked HWP MSR access
> 
> HWP MSR 0x771 can be only read on a CPU which supports HWP and enabled.
> Hence intel_pstate_get_hwp_cap() can only be called when hwp_active is
> true.
> 
> Reported-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Did Sebastian _Reichel_ report it, too?

> Closes: https://lore.kernel.org/linux-pm/20240529155740.Hq2Hw7be@linutronix.de/

Because this my report ;)

> Fixes: e8217b4bece3 ("cpufreq: intel_pstate: Update the maximum CPU frequency consistently")
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Sebastian