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authorPatryk Duda <pdk@semihalf.com>2021-05-18 16:07:58 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-18 13:42:22 +0200
commitb9fcf469b04e3067be10c20cb519f2be88176cda (patch)
tree9f010c5992349cdb170290a8445dfaa5082306dd
parent91846be7f54b43574e1d95be6ed2151efe1ec0d8 (diff)
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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>
-rw-r--r--drivers/platform/chrome/cros_ec_proto.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index aa7f7aa77297..a7404d69b2d3 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -279,6 +279,15 @@ 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,