@@ -63,6 +63,12 @@ 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 replace = false;
+module_param(replace, bool, 0444);
+MODULE_PARM_DESC(replace,
+ "replace acpi-cpufreq driver upon init if necessary");
+extern void acpi_cpufreq_exit(void);
+
static struct cpufreq_driver amd_pstate_driver;
/**
@@ -643,6 +649,7 @@ static struct cpufreq_driver amd_pstate_driver = {
static int __init amd_pstate_init(void)
{
+ const char *current_driver;
int ret;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
@@ -653,9 +660,15 @@ static int __init amd_pstate_init(void)
return -ENODEV;
}
- /* don't keep reloading if cpufreq_driver exists */
- if (cpufreq_get_current_driver())
- return -EEXIST;
+ current_driver = cpufreq_get_current_driver();
+ if (current_driver) {
+ if (replace && strcmp(current_driver, "acpi-cpufreq") == 0) {
+ acpi_cpufreq_exit();
+ } else {
+ pr_info("This processor supports amd-pstate, you can enable it with amd_pstate.replace=1\n");
+ return -EEXIST;
+ }
+ }
/* capability check */
if (boot_cpu_has(X86_FEATURE_CPPC)) {
`amd-pstate` can be compiled as a module. This however can be a deficiency because `acpi-cpufreq` will be loaded earlier when compiled into the kernel meaning `amd-pstate` doesn't get a chance. `acpi-cpufreq` is also unable to be unloaded in this circumstance. To better improve the usability of `amd-pstate` when compiled as a module, add an optional module parameter that will force it to replace other cpufreq drivers at startup. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- v1->v2: * Update to changes from v1. * Verify the driver being matched is acpi-cpufreq. * Show a message letting users know they can use amd-pstate. drivers/cpufreq/amd-pstate.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)