linux-kernel - [char-misc 2/2 for 4.11] mei: don't wait for os version message reply

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Date:   Sun,  5 Mar 2017 21:40:42 +0200
From:   Tomas Winkler <tomas.winkler@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Alexander Usyskin <alexander.usyskin@...el.com>,
        linux-kernel@...r.kernel.org, "#4 . 10+" <stable@...r.kernel.org>,
        Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc 2/2 for 4.11] mei: don't wait for os version message reply

From: Alexander Usyskin <alexander.usyskin@...el.com>

The driver still struggles with firmwares that do not replay to the OS
version request. It is safe not waiting for the replay. First, the driver
doesn't do anything with the replay second the connection is closed
immediately, hence the packet will be just safely discarded in case it
is received and last the driver won't get stuck if the firmware won't
reply.

Cc: <stable@...r.kernel.org> #4.10+
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/bus-fixup.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 3600c9993a98..29f2daed37e0 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -112,11 +112,9 @@ struct mkhi_msg {
 
 static int mei_osver(struct mei_cl_device *cldev)
 {
-	int ret;
 	const size_t size = sizeof(struct mkhi_msg_hdr) +
 			    sizeof(struct mkhi_fwcaps) +
 			    sizeof(struct mei_os_ver);
-	size_t length = 8;
 	char buf[size];
 	struct mkhi_msg *req;
 	struct mkhi_fwcaps *fwcaps;
@@ -137,15 +135,7 @@ static int mei_osver(struct mei_cl_device *cldev)
 	os_ver = (struct mei_os_ver *)fwcaps->data;
 	os_ver->os_type = OSTYPE_LINUX;
 
-	ret = __mei_cl_send(cldev->cl, buf, size, mode);
-	if (ret < 0)
-		return ret;
-
-	ret = __mei_cl_recv(cldev->cl, buf, length, 0);
-	if (ret < 0)
-		return ret;
-
-	return 0;
+	return __mei_cl_send(cldev->cl, buf, size, mode);
 }
 
 static void mei_mkhi_fix(struct mei_cl_device *cldev)
@@ -160,7 +150,7 @@ static void mei_mkhi_fix(struct mei_cl_device *cldev)
 		return;
 
 	ret = mei_osver(cldev);
-	if (ret)
+	if (ret < 0)
 		dev_err(&cldev->dev, "OS version command failed %d\n", ret);
 
 	mei_cldev_disable(cldev);
-- 
2.7.4