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authorPatryk Duda <pdk@semihalf.com>2021-05-18 16:07:58 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-22 11:45:32 +0200
commit369abdf45afb326b7f34709f528eb8969e5883a4 (patch)
treef5c94ab6a4296b0012aac212673a65bf6835cd9d
parent3847466426db0d244a233772e3faa491de2ab156 (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 dbad14716da4..b8e90c1a5e26 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -217,6 +217,15 @@ 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,