linux-kernel - [char-misc-next] mei: ignore not found client in the enumeration

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Date:   Mon,  6 Aug 2018 17:47:33 +0300
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, stable@...r.kernel.org,
        Tomas Winkler <tomas.winkler@...el.com>,
        Heiner Kallweit <hkallweit1@...il.com>
Subject: [char-misc-next] mei: ignore not found client in the enumeration

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

Some of the ME clients are available only for BIOS operation and are
removed during hand off to an OS. However the removal is not instant.
A client may be visible on the client list when the mei driver requests
for enumeration, while the subsequent request for properties will be
answered with client not found error value. The default behavior
for an error is to perform client reset while this error is harmless and
the link reset should be prevented. This issue started to be visible due to
suspend/resume timing changes. Currently reported only on the Haswell
based system.

Fixes:
[33.564957] mei_me 0000:00:16.0: hbm: properties response: wrong status = 1 CLIENT_NOT_FOUND
[33.564978] mei_me 0000:00:16.0: mei_irq_read_handler ret = -71.
[33.565270] mei_me 0000:00:16.0: unexpected reset: dev_state = INIT_CLIENTS fw status = 1E000255 60002306 00000200 00004401 00000000 00000010

Cc: <stable@...r.kernel.org>
Reported-by: Heiner Kallweit <hkallweit1@...il.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/hbm.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index f15d44bda28e..fa0f8e91e86f 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -1244,15 +1244,18 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 
 		props_res = (struct hbm_props_response *)mei_msg;
 
-		if (props_res->status) {
+		if (props_res->status == MEI_HBMS_CLIENT_NOT_FOUND) {
+			dev_dbg(dev->dev, "hbm: properties response: %d CLIENT_NOT_FOUND\n",
+				props_res->me_addr);
+		} else if (props_res->status) {
 			dev_err(dev->dev, "hbm: properties response: wrong status = %d %s\n",
 				props_res->status,
 				mei_hbm_status_str(props_res->status));
 			return -EPROTO;
+		} else {
+			mei_hbm_me_cl_add(dev, props_res);
 		}
 
-		mei_hbm_me_cl_add(dev, props_res);
-
 		/* request property for the next client */
 		if (mei_hbm_prop_req(dev, props_res->me_addr + 1))
 			return -EIO;
-- 
2.14.4