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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.4 12/80] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()
Date:   Mon,  3 Sep 2018 18:48:50 +0200
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4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 0602088b10a7c0b4e044a810678ef93d7cc5bf48 ]

The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16.7 are:

[FUNC] msleep
drivers/usb/gadget/udc/r8a66597-udc.c, 839:
		msleep in init_controller
drivers/usb/gadget/udc/r8a66597-udc.c, 96:
		init_controller in r8a66597_usb_disconnect
drivers/usb/gadget/udc/r8a66597-udc.c, 93:
		spin_lock in r8a66597_usb_disconnect

[FUNC] msleep
drivers/usb/gadget/udc/r8a66597-udc.c, 835:
		msleep in init_controller
drivers/usb/gadget/udc/r8a66597-udc.c, 96:
		init_controller in r8a66597_usb_disconnect
drivers/usb/gadget/udc/r8a66597-udc.c, 93:
		spin_lock in r8a66597_usb_disconnect

To fix these bugs, msleep() is replaced with mdelay().

This bug is found by my static analysis tool (DSAC-2) and checked by
my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/gadget/udc/r8a66597-udc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/udc/r8a66597-udc.c
+++ b/drivers/usb/gadget/udc/r8a66597-udc.c
@@ -835,11 +835,11 @@ static void init_controller(struct r8a66
 
 		r8a66597_bset(r8a66597, XCKE, SYSCFG0);
 
-		msleep(3);
+		mdelay(3);
 
 		r8a66597_bset(r8a66597, PLLC, SYSCFG0);
 
-		msleep(1);
+		mdelay(1);
 
 		r8a66597_bset(r8a66597, SCKE, SYSCFG0);