From: Patryk Duda Date: Tue, 18 May 2021 14:07:58 +0000 (+0200) Subject: platform/chrome: cros_ec_proto: Send command again when timeout occurs X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3abc16af57c9939724df92fcbda296b25cc95168;p=linux.git 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 --- diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index aa7f7aa772971..a7404d69b2d32 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,