Change the `amd-pstate` driver as the built-in type which can help to
load the driver before the acpi_cpufreq driver as the default pstate
driver for the AMD processors.
for the processors do not have the dedicated MSR functions, add
`amd-pstate=legacy_cppc` to grub which enable shared memmory interface
to communicate with cppc_acpi module to control pstate hints.
Signed-off-by: Perry Yuan <[email protected]>
---
drivers/cpufreq/amd-pstate.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index ace7d50cf2ac..14906431dc15 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -59,10 +59,7 @@
* we disable it by default to go acpi-cpufreq on these processors and add a
* module parameter to be able to enable it manually for debugging.
*/
-static bool shared_mem = false;
-module_param(shared_mem, bool, 0444);
-MODULE_PARM_DESC(shared_mem,
- "enable amd-pstate on processors with shared memory solution (false = disabled (default), true = enabled)");
+static bool shared_mem __read_mostly;
static struct cpufreq_driver amd_pstate_driver;
@@ -653,16 +650,22 @@ static int __init amd_pstate_init(void)
return ret;
}
+device_initcall(amd_pstate_init);
-static void __exit amd_pstate_exit(void)
+static int __init amd_pstate_param(char *str)
{
- cpufreq_unregister_driver(&amd_pstate_driver);
+ if (!str)
+ return -EINVAL;
- amd_pstate_enable(false);
-}
+ /* enable shared memory type CPPC ,if you processor has no MSR, you have to add this
+ * to your grub to make cppc driver loaded successfully.
+ */
+ if (!strcmp(str, "legacy_cppc"))
+ shared_mem = true;
-module_init(amd_pstate_init);
-module_exit(amd_pstate_exit);
+ return 0;
+}
+early_param("amd-pstate", amd_pstate_param);
MODULE_AUTHOR("Huang Rui <[email protected]>");
MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");
--
2.34.1