Messages in this thread | | | Date | Thu, 28 Apr 2022 14:52:33 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH 22/22] firmware: arm_scmi: Add SCMIv3.1 PERFORMANCE_LIMITS_SET checks |
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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 😄.
-- Regards, Sudeep
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