On Tue, Dec 22, 2020 at 07:37:22PM -0800, Florian Fainelli wrote: > > > On 12/22/2020 6:56 AM, 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. > > > > Signed-off-by: Jim Quinlan <jim2101...@gmail.com> > > This looks good to me, just one question below: > > [snip] > > > @@ -111,6 +145,8 @@ static int smc_send_message(struct scmi_chan_info > > *cinfo, > > shmem_tx_prepare(scmi_info->shmem, xfer); > > > > arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res); > > + if (scmi_info->irq) > > + wait_for_completion(&scmi_info->tx_complete); > > Do we need this to have a preceding call to reinit_completion()? It does > not look like this is going to make any practical difference but there > are drivers doing that for correctness.
Why do you think that might not cause any issue ? After first message is completed and ISR is executed, the completion flag remains done for ever. So practically 2nd message onwards won't block in wait_for_completion which means return from smc/hvc is actually completion too which is clearly wrong or am I missing something ? Jim, please confirm either way. If you agree I can add the below snippet, no need to repost. Regards, Sudeep -- diff --git i/drivers/firmware/arm_scmi/smc.c w/drivers/firmware/arm_scmi/smc.c index fd41d436e34b..86eac0831d3c 100644 --- i/drivers/firmware/arm_scmi/smc.c +++ w/drivers/firmware/arm_scmi/smc.c @@ -144,6 +145,8 @@ static int smc_send_message(struct scmi_chan_info *cinfo, shmem_tx_prepare(scmi_info->shmem, xfer); + if (scmi_info->irq) + reinit_completion(&scmi_info->tx_complete); arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res); if (scmi_info->irq) wait_for_completion(&scmi_info->tx_complete);