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cpufreq: amd-pstate: Propagate cppc_set_auto_sel() errors on mode change

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amd_pstate_change_mode_without_dvr_change() iterates over the online CPUs
and calls cppc_set_auto_sel() to enable or disable hardware autonomous
selection, but discards its return value and unconditionally returns 0.

If the firmware rejects the request, the failure is hidden: the cpufreq
core records the mode transition as successful while the hardware stays in
its previous autonomous-selection state.  The software mode and the actual
hardware behaviour then disagree, breaking the expected frequency scaling.

Check the return value of cppc_set_auto_sel() and propagate the first
error to the caller so the sysfs write reports the failure.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/bug/linux-d114a94a-655b-43a6-91b1-9484889726c9
Fixes: 3ca7bc818d ("cpufreq: amd-pstate: Add guided mode control support via sysfs")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20260921190235.3651688-2-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <superm1@kernel.org>
This commit is contained in:
Mario Limonciello 2026-09-21 14:02:33 -05:00 committed by Mario Limonciello
parent f6d3cbc639
commit 8de7050371
1 changed files with 4 additions and 1 deletions
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5
drivers/cpufreq/amd-pstate.c
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@ -1822,6 +1822,7 @@ static int amd_pstate_unregister_driver(int dummy)
static int amd_pstate_change_mode_without_dvr_change(int mode)
{
int cpu = 0;
int ret;
cppc_state = mode;
@ -1829,7 +1830,9 @@ static int amd_pstate_change_mode_without_dvr_change(int mode)
return 0;
for_each_online_cpu(cpu) {
cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
ret = cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
if (ret)
return ret;
}
return 0;