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authorCristian Marussi <cristian.marussi@arm.com>2020-04-20 18:23:15 +0300
committerSudeep Holla <sudeep.holla@arm.com>2020-04-20 19:25:26 +0300
commitc5bceb98ce0e4ae8057a386c5171a868213fe226 (patch)
tree79ce17a9b12c404fea3383c3f84fbbc142d810b5 /drivers/firmware/arm_scmi
parentd04fb2b2ddefad7c00edd29c1ed40188ce8f12a2 (diff)
downloadlinux-c5bceb98ce0e4ae8057a386c5171a868213fe226.tar.xz
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: 4d09852b6f01 ("firmware: arm_scmi: Add support for notifications message processing") Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware/arm_scmi')
-rw-r--r--drivers/firmware/arm_scmi/driver.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 07de196f15aa..fec308e47b9d 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -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);