linux-kernel - [char-misc-next 4/4] mei: do not overwrite state on hw start

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Date:   Tue, 15 Feb 2022 10:04:38 +0200
From:   Tomas Winkler <tomas.winkler@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Alexander Usyskin <alexander.usyskin@...el.com>,
        Vitaly Lubart <vitaly.lubart@...el.com>,
        linux-kernel@...r.kernel.org,
        Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc-next 4/4] mei: do not overwrite state on hw start

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

During the hardware start sequence, do not overwrite the driver state
and do not proceed with the initialization sequence if the state
was changed while the driver was waiting for the start interrupt.

This can happen if the driver's removal/stop procedure was triggered
from the parent level while the driver is waiting for the start
interrupt. This may lead to stray the reset work or the timer
after driver were removed.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/init.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index f79076c67256..eb052005ca86 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -161,6 +161,11 @@ int mei_reset(struct mei_device *dev)
 		return ret;
 	}
 
+	if (dev->dev_state != MEI_DEV_RESETTING) {
+		dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state);
+		return 0;
+	}
+
 	dev_dbg(dev->dev, "link is established start sending messages.\n");
 
 	mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS);
-- 
2.34.1