Re: [RFC PATCH 02/10] firmware: arm_scmi: Add missing xfer reinit_completion

Hi,

On Mon, Jun 07, 2021 at 06:42:57PM +0100, Sudeep Holla wrote:

On Sun, Jun 06, 2021 at 11:12:24PM +0100, Cristian Marussi wrote:

quoted

Reusing timed out xfers in a loop can lead to issue if completion was not
properly reinitialized.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index bee33f9c2032..759ae4a23e74 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c

@@ -448,6 +448,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
 			      xfer->hdr.poll_completion);

 	xfer->hdr.status = SCMI_SUCCESS;
+	reinit_completion(&xfer->done);

What could happen after xfer_get_init->scmi_xfer_get->reinit_completion
that it needs to be re-initialised again. I don't see any reason for this ?
If there are, please state them explicitly. If this is needed, I would drop
the one in scmi_xfer_get().

The reason, like I explained in the other reply in hdr.status, is the
possibility of do_xfer loops and being more defensive.

I agree that if what I blabbed in the other email is acceptable, I could
drop the reinit_completion in xfer_get() and just use it before
send_message().

Thanks,
Cristian

--
Regards,
Sudeep

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