cpufreq: amd-pstate: Bail out if min/max/nominal_freq is 0

The amd-pstate driver cannot work when the min_freq, nominal_freq or
the max_freq is zero. When this happens it is prudent to error out
early on rather than waiting failing at the time of the governor
initialization.

Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 3836d62b54ef3612c4bd0ed1dbdaada529756bd6..960fead0b83e2d1af3a999d8bdd42a327cce9370 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -839,9 +839,11 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
        nominal_freq = READ_ONCE(cpudata->nominal_freq);
        lowest_nonlinear_freq = READ_ONCE(cpudata->lowest_nonlinear_freq);
 
-       if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-               dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-                       min_freq, max_freq);
+       if (min_freq <= 0 || max_freq <= 0 ||
+           nominal_freq <= 0 || min_freq > max_freq) {
+               dev_err(dev,
+                       "min_freq(%d) or max_freq(%d) or nominal_freq (%d) value is incorrect, check _CPC in ACPI tables\n",
+                       min_freq, max_freq, nominal_freq);
                ret = -EINVAL;
                goto free_cpudata1;
        }
@@ -1299,9 +1301,11 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
        max_freq = READ_ONCE(cpudata->max_freq);
        nominal_freq = READ_ONCE(cpudata->nominal_freq);
        lowest_nonlinear_freq = READ_ONCE(cpudata->lowest_nonlinear_freq);
-       if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-               dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-                               min_freq, max_freq);
+       if (min_freq <= 0 || max_freq <= 0 ||
+           nominal_freq <= 0 || min_freq > max_freq) {
+               dev_err(dev,
+                       "min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect, check _CPC in ACPI tables\n",
+                       min_freq, max_freq, nominal_freq);
                ret = -EINVAL;
                goto free_cpudata1;
        }