Commit 4654e9f9 authored Mar 30, 2023 by Wyes Karny Committed by Rafael J. Wysocki Apr 11, 2023

amd-pstate: Fix amd_pstate mode switch



amd_pstate mode can be changed by writing the mode name to the `status`
sysfs. But some combinations are not working. Fix this issue by taking
care of the edge cases.

Before the fix the mode change combination test fails:

 #./pst_test.sh
Test passed: from: disable, to
Test passed: from: disable, to disable
Test failed: 1, From mode: disable, to mode: passive
Test failed: 1, From mode: disable, to mode: active
Test failed: 1, From mode: passive, to mode: active
Test passed: from: passive, to disable
Test failed: 1, From mode: passive, to mode: passive
Test failed: 1, From mode: passive, to mode: active
Test failed: 1, From mode: active, to mode: active
Test passed: from: active, to disable
Test failed: 1, From mode: active, to mode: passive
Test failed: 1, From mode: active, to mode: active

After the fix test passes:

 #./pst_test.sh
Test passed: from: disable, to
Test passed: from: disable, to disable
Test passed: from: disable, to passive
Test passed: from: disable, to active
Test passed: from: passive, to active
Test passed: from: passive, to disable
Test passed: from: passive, to passive
Test passed: from: passive, to active
Test passed: from: active, to active
Test passed: from: active, to disable
Test passed: from: active, to passive
Test passed: from: active, to active

Fixes: abd61c08 ("cpufreq: amd-pstate: add driver working mode switch support")
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 09a9639e

drivers/cpufreq/amd-pstate.c

+8 −10

Original line number	Diff line number	Diff line
		@@ -840,22 +840,20 @@ static int amd_pstate_update_status(const char *buf, size_t size)

		switch(mode_idx) {
		case AMD_PSTATE_DISABLE:
		if (!current_pstate_driver)
		return -EINVAL;
		if (cppc_state == AMD_PSTATE_ACTIVE)
		return -EBUSY;
		if (current_pstate_driver) {
		cpufreq_unregister_driver(current_pstate_driver);
		amd_pstate_driver_cleanup();
		}
		break;
		case AMD_PSTATE_PASSIVE:
		if (current_pstate_driver) {
		if (current_pstate_driver == &amd_pstate_driver)
		return 0;
		cpufreq_unregister_driver(current_pstate_driver);
		cppc_state = AMD_PSTATE_PASSIVE;
		current_pstate_driver = &amd_pstate_driver;
		}

		current_pstate_driver = &amd_pstate_driver;
		cppc_state = AMD_PSTATE_PASSIVE;
		ret = cpufreq_register_driver(current_pstate_driver);
		break;
		case AMD_PSTATE_ACTIVE:
		@@ -863,10 +861,10 @@ static int amd_pstate_update_status(const char *buf, size_t size)
		if (current_pstate_driver == &amd_pstate_epp_driver)
		return 0;
		cpufreq_unregister_driver(current_pstate_driver);
		current_pstate_driver = &amd_pstate_epp_driver;
		cppc_state = AMD_PSTATE_ACTIVE;
		}

		current_pstate_driver = &amd_pstate_epp_driver;
		cppc_state = AMD_PSTATE_ACTIVE;
		ret = cpufreq_register_driver(current_pstate_driver);
		break;
		default: