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authorPatryk Duda <pdk@semihalf.com>2021-05-18 17:07:58 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-18 14:40:37 +0300
commit00cdb2fb4df1d3e8e69751c8da22772ef1f7de07 (patch)
tree43f2cf1e750effdac6b8d72b9192860c1cbdfacb
parentb2e72e53cd26c1bccf42b94b0faea47ef9e55461 (diff)
downloadlinux-00cdb2fb4df1d3e8e69751c8da22772ef1f7de07.tar.xz
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 ea5149efcbea..9f698a7aad12 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,