| Message ID | 20220330150551.2573938-23-cristian.marussi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | SCMIv3.1 Miscellaneous changes | expand |
On Wed, Mar 30, 2022 at 04:05:51PM +0100, Cristian Marussi wrote: > Starting with SCMIv3.1, the PERFORMANCE_LIMITS_SET command allows a user > to request only one between max and min ranges to be changed, while leaving > the other untouched if set to zero in the request; anyway SCMIv3.1 states > also explicitly that you cannot leave both of those unchanged (zeroed) when > issuing such command: add a proper check for this condition. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > drivers/firmware/arm_scmi/perf.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c > index 65ffda5495d6..8f4051aca220 100644 > --- a/drivers/firmware/arm_scmi/perf.c > +++ b/drivers/firmware/arm_scmi/perf.c > @@ -423,6 +423,9 @@ static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph, > struct scmi_perf_info *pi = ph->get_priv(ph); > struct perf_dom_info *dom = pi->dom_info + domain; > > + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x3 && !max_perf && !min_perf) > + return -EINVAL; > + Do we really need the version check here ? I agree it was explicitly added in v3.1, but it makes sense on any version really. No ?
On Thu, Apr 28, 2022 at 02:13:57PM +0100, Sudeep Holla wrote: > On Wed, Mar 30, 2022 at 04:05:51PM +0100, Cristian Marussi wrote: > > Starting with SCMIv3.1, the PERFORMANCE_LIMITS_SET command allows a user > > to request only one between max and min ranges to be changed, while leaving > > the other untouched if set to zero in the request; anyway SCMIv3.1 states > > also explicitly that you cannot leave both of those unchanged (zeroed) when > > issuing such command: add a proper check for this condition. > > > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > > --- > > drivers/firmware/arm_scmi/perf.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c > > index 65ffda5495d6..8f4051aca220 100644 > > --- a/drivers/firmware/arm_scmi/perf.c > > +++ b/drivers/firmware/arm_scmi/perf.c > > @@ -423,6 +423,9 @@ static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph, > > struct scmi_perf_info *pi = ph->get_priv(ph); > > struct perf_dom_info *dom = pi->dom_info + domain; > > > > + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x3 && !max_perf && !min_perf) > > + return -EINVAL; > > + > > Do we really need the version check here ? I agree it was explicitly added > in v3.1, but it makes sense on any version really. No ? Indeed seemed a silly patch also to me but given that only in v3.1 it is explicitly stated that you cannot issue this command with both min and max ZEROED I though this could have broken older fw that allowed setting PERF_LIMITS_SET max=0 min=0 ....maybe overthought ... Thanks, Cristian
On Thu, Apr 28, 2022 at 02:49:48PM +0100, Cristian Marussi wrote: > On Thu, Apr 28, 2022 at 02:13:57PM +0100, Sudeep Holla wrote: > > On Wed, Mar 30, 2022 at 04:05:51PM +0100, Cristian Marussi wrote: > > > Starting with SCMIv3.1, the PERFORMANCE_LIMITS_SET command allows a user > > > to request only one between max and min ranges to be changed, while leaving > > > the other untouched if set to zero in the request; anyway SCMIv3.1 states > > > also explicitly that you cannot leave both of those unchanged (zeroed) when > > > issuing such command: add a proper check for this condition. > > > > > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > > > --- > > > drivers/firmware/arm_scmi/perf.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c > > > index 65ffda5495d6..8f4051aca220 100644 > > > --- a/drivers/firmware/arm_scmi/perf.c > > > +++ b/drivers/firmware/arm_scmi/perf.c > > > @@ -423,6 +423,9 @@ static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph, > > > struct scmi_perf_info *pi = ph->get_priv(ph); > > > struct perf_dom_info *dom = pi->dom_info + domain; > > > > > > + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x3 && !max_perf && !min_perf) > > > + return -EINVAL; > > > + > > > > Do we really need the version check here ? I agree it was explicitly added > > in v3.1, but it makes sense on any version really. No ? > > Indeed seemed a silly patch also to me but given that only in v3.1 it is > explicitly stated that you cannot issue this command with both min and > max ZEROED I though this could have broken older fw that allowed > setting PERF_LIMITS_SET max=0 min=0 > > ....maybe overthought ... Hmm, let's keep it unconditional for now. We can add if someone reports broken firmware. BTW there are no users in the kernel
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c index 65ffda5495d6..8f4051aca220 100644 --- a/drivers/firmware/arm_scmi/perf.c +++ b/drivers/firmware/arm_scmi/perf.c @@ -423,6 +423,9 @@ static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph, struct scmi_perf_info *pi = ph->get_priv(ph); struct perf_dom_info *dom = pi->dom_info + domain; + if (PROTOCOL_REV_MAJOR(pi->version) >= 0x3 && !max_perf && !min_perf) + return -EINVAL; + if (dom->fc_info && dom->fc_info->limit_set_addr) { iowrite32(max_perf, dom->fc_info->limit_set_addr); iowrite32(min_perf, dom->fc_info->limit_set_addr + 4);
Starting with SCMIv3.1, the PERFORMANCE_LIMITS_SET command allows a user to request only one between max and min ranges to be changed, while leaving the other untouched if set to zero in the request; anyway SCMIv3.1 states also explicitly that you cannot leave both of those unchanged (zeroed) when issuing such command: add a proper check for this condition. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/perf.c | 3 +++ 1 file changed, 3 insertions(+)