[PATCH v10 5/8] cpufreq: amd-pstate: Bail out if min/max/nominal_freq is 0

Perry Yuan
2024-03-25T03:04:24Z

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.

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>
---
drivers/cpufreq/amd-pstate.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 132330b4942f..6708c436e1a2 100644
--- 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\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\n",
+ min_freq, max_freq, nominal_freq);
ret = -EINVAL;
goto free_cpudata1;
}
--
2.34.1