Commit c5bceb98 authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Fix handling of unexpected delayed responses 

Upon reception of an unexpected bogus delayed response, clear the channel
and bail-out safely.

Link: https://lore.kernel.org/r/20200420152315.21008-5-cristian.marussi@arm.com


Fixes: 4d09852b ("firmware: arm_scmi: Add support for notifications message processing")
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent d04fb2b2

drivers/firmware/arm_scmi/driver.c

+15 −0
Original line number Diff line number Diff line
@@ -247,6 +247,21 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, 
	}



	xfer = &minfo->xfer_block[xfer_id];

	/*

	 * Even if a response was indeed expected on this slot at this point,

	 * a buggy platform could wrongly reply feeding us an unexpected

	 * delayed response we're not prepared to handle: bail-out safely

	 * blaming firmware.

	 */

	if (unlikely(msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done)) {

		dev_err(dev,

			"Delayed Response for %d not expected! Buggy F/W ?\n",

			xfer_id);

		info->desc->ops->clear_channel(cinfo);

		/* It was unexpected, so nobody will clear the xfer if not us */

		__scmi_xfer_put(minfo, xfer);

		return;

	}



	scmi_dump_header_dbg(dev, &xfer->hdr);