can: mcp251x: mcp251x_restart_work_handler(): Fix potential force_quit race condition

[ Upstream commit 27a0e54b ]

In mcp251x_restart_work_handler() the variable to stop the interrupt
handler (priv->force_quit) is reset after the chip is restarted and thus
a interrupt might occur.

This patch fixes the potential race condition by resetting force_quit
before enabling interrupts.
Signed-off-by: Timo Schlüßler <schluessler@krause.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/can/spi/mcp251x.c

@@ -773,6 +773,7 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
 	if (priv->after_suspend) {
 		mcp251x_hw_reset(spi);
 		mcp251x_setup(net, spi);
+		priv->force_quit = 0;
 		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
 			mcp251x_set_normal_mode(spi);
 		} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
@@ -784,7 +785,6 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
 			mcp251x_hw_sleep(spi);
 		}
 		priv->after_suspend = 0;
-		priv->force_quit = 0;
 	}
 
 	if (priv->restart_tx) {