| Message ID | 20220714134342.3498384-1-quic_kshivnan@quicinc.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v2,1/1] PM: QoS: Add check to make sure CPU freq is non-negative | expand |
On Thu, Jul 14, 2022 at 3:44 PM Shivnandan Kumar <quic_kshivnan@quicinc.com> wrote: > > CPU frequency should never be negative. > If some client driver calls freq_qos_update_request with some > value greater than INT_MAX, then it will set max CPU freq at > fmax but it will add plist node with some negative priority. > plist node has priority from INT_MIN (highest) to INT_MAX > (lowest). Once priority is set as negative, another client > will not be able to reduce CPU frequency. Adding check to > make sure CPU freq is non-negative will fix this problem. The changelog doesn't match the patch any more, please rewrite it. > > Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com> > > --- > v1->v2 > -addressed comments from Rafael > -changed commit text accordingly > > kernel/power/qos.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/power/qos.c b/kernel/power/qos.c > index ec7e1e85923e..27e6596f287a 100644 > --- a/kernel/power/qos.c > +++ b/kernel/power/qos.c > @@ -531,7 +531,7 @@ int freq_qos_add_request(struct freq_constraints *qos, > { > int ret; > > - if (IS_ERR_OR_NULL(qos) || !req) > + if (IS_ERR_OR_NULL(qos) || !req || value < FREQ_QOS_MIN_DEFAULT_VALUE) > return -EINVAL; > > if (WARN(freq_qos_request_active(req), > @@ -563,7 +563,7 @@ EXPORT_SYMBOL_GPL(freq_qos_add_request); > */ > int freq_qos_update_request(struct freq_qos_request *req, s32 new_value) > { > - if (!req) > + if (!req || new_value < FREQ_QOS_MIN_DEFAULT_VALUE) > return -EINVAL; > > if (WARN(!freq_qos_request_active(req), > -- > 2.25.1 >
diff --git a/kernel/power/qos.c b/kernel/power/qos.c index ec7e1e85923e..27e6596f287a 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -531,7 +531,7 @@ int freq_qos_add_request(struct freq_constraints *qos, { int ret; - if (IS_ERR_OR_NULL(qos) || !req) + if (IS_ERR_OR_NULL(qos) || !req || value < FREQ_QOS_MIN_DEFAULT_VALUE) return -EINVAL; if (WARN(freq_qos_request_active(req), @@ -563,7 +563,7 @@ EXPORT_SYMBOL_GPL(freq_qos_add_request); */ int freq_qos_update_request(struct freq_qos_request *req, s32 new_value) { - if (!req) + if (!req || new_value < FREQ_QOS_MIN_DEFAULT_VALUE) return -EINVAL; if (WARN(!freq_qos_request_active(req),
CPU frequency should never be negative. If some client driver calls freq_qos_update_request with some value greater than INT_MAX, then it will set max CPU freq at fmax but it will add plist node with some negative priority. plist node has priority from INT_MIN (highest) to INT_MAX (lowest). Once priority is set as negative, another client will not be able to reduce CPU frequency. Adding check to make sure CPU freq is non-negative will fix this problem. Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com> --- v1->v2 -addressed comments from Rafael -changed commit text accordingly kernel/power/qos.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)