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Subject[PATCH 1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()
Date
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>
---
drivers/usb/gadget/udc/r8a66597-udc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/r8a66597-udc.c b/drivers/usb/gadget/udc/r8a66597-udc.c
index a3ecce62662b..24ee9867964b 100644
--- a/drivers/usb/gadget/udc/r8a66597-udc.c
+++ b/drivers/usb/gadget/udc/r8a66597-udc.c
@@ -832,11 +832,11 @@ static void init_controller(struct r8a66597 *r8a66597)

r8a66597_bset(r8a66597, XCKE, SYSCFG0);

- msleep(3);
+ mdelay(3);

r8a66597_bset(r8a66597, PLLC, SYSCFG0);

- msleep(1);
+ mdelay(1);

r8a66597_bset(r8a66597, SCKE, SYSCFG0);

--
2.17.0
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