From 3abc16af57c9939724df92fcbda296b25cc95168 Mon Sep 17 00:00:00 2001 From: Patryk Duda Date: Tue, 18 May 2021 16:07:58 +0200 Subject: [PATCH] platform/chrome: cros_ec_proto: Send command again when timeout occurs 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: # 4.4+ Signed-off-by: Patryk Duda Link: https://lore.kernel.org/r/20210518140758.29318-1-pdk@semihalf.com Signed-off-by: Benson Leung --- drivers/platform/chrome/cros_ec_proto.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index aa7f7aa..a7404d6 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, -- 2.7.4