Messages in this thread | | | From | Jim Quinlan <> | Date | Fri, 13 Nov 2020 10:12:24 -0500 | Subject | Re: [PATCH v2 2/2] firmware: arm_scmi: Augment SMC/HVC to allow optional interrupt |
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On Fri, Nov 13, 2020 at 9:36 AM Sudeep Holla <sudeep.holla@arm.com> wrote: > > On Fri, Nov 13, 2020 at 09:26:43AM -0500, Jim Quinlan wrote: > > Hi, these are fast calls. Regards, Jim > > > > > > On Fri, Nov 13, 2020 at 4:47 AM Sudeep Holla <sudeep.holla@arm.com> wrote: > > > > > > On Thu, Nov 12, 2020 at 12:56:27PM -0500, Jim Quinlan wrote: > > > > The SMC/HVC SCMI transport is modified to allow the completion of an SCMI > > > > message to be indicated by an interrupt rather than the return of the smc > > > > call. This accommodates the existing behavior of the BrcmSTB SCMI > > > > "platform" whose SW is already out in the field and cannot be changed. > > > > > > > > > > Sorry for missing to check with you earlier. Are these not fast smc calls ? > > > Can we check the SMC Function IDs for the same and expect IRQ to be present > > > if they are not fast calls ? > > Hi, if I understand you correctly you want to do something like this: > > > > if (! ARM_SMCCC_IS_FAST_CALL(func_id)) { > > /* look for irq and request it */ > > } > > > > Yes. > > > But we do use fast calls. > > What was the rationale for retaining fast SMC calls but use IRQ for Tx > completion ? > > Is it because you offload it to some other microprocessor and don't > continue execution on secure side in whcih case you can afford fast call ?
Hi Sudeep, I have an answer for this but allow me time to contact the platform FW engineer to make sure I have the full picture -- this may take a day or two. Regardless, our implementation has already "shipped" to customers for some time so we may not be able to change it. Regards, Jim > > > -- > Regards, > Sudeep [unhandled content-type:application/pkcs7-signature] | |