Commit 54748ae6 authored May 18, 2021 by Patryk Duda Committed by Greg Kroah-Hartman Sep 22, 2021

platform/chrome: cros_ec_proto: Send command again when timeout occurs



commit 3abc16af57c9939724df92fcbda296b25cc95168 upstream.

Sometimes kernel is trying to probe Fingerprint MCU (FPMCU) when it
hasn't initialized SPI yet. This can happen because FPMCU is restarted
during system boot and kernel can send message in short window
eg. between sysjump to RW and SPI initialization.

Cc: <stable@vger.kernel.org> # 4.4+
Signed-off-by: Patryk Duda <pdk@semihalf.com>
Link: https://lore.kernel.org/r/20210518140758.29318-1-pdk@semihalf.com


Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 2cc559a4

drivers/platform/chrome/cros_ec_proto.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -219,6 +219,15 @@ static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
		msg->insize = sizeof(struct ec_response_get_protocol_info);

		ret = send_command(ec_dev, msg);
		/*
		* Send command once again when timeout occurred.
		* Fingerprint MCU (FPMCU) is restarted during system boot which
		* introduces small window in which FPMCU won't respond for any
		* messages sent by kernel. There is no need to wait before next
		* attempt because we waited at least EC_MSG_DEADLINE_MS.
		*/
		if (ret == -ETIMEDOUT)
		ret = send_command(ec_dev, msg);

		if (ret < 0) {
		dev_dbg(ec_dev->dev,