2015-04-24 16:03:58

by Larry Finger

Subject: [PATCH for 4.1] rtlwifi: rtl8192cu: Fix kernel deadlock

The USB mini-driver in rtlwifi, which is used by rtl8192cu, issues a call to
usb_control_msg() with a timeout value of 0. In some instances where the
interface is shutting down, this infinite wait results in a CPU deadlock. A
one second timeout fixes this problem without affecting any normal operations.

This bug is reported at https://bugzilla.novell.com/show_bug.cgi?id=927786.

Reported-by: Bernhard Wiedemann <[email protected]>
Tested-by: Bernhard Wiedemann <[email protected]>
Signed-off-by: Larry Finger <[email protected]>
Cc: Stable <[email protected]>
Cc: Bernhard Wiedemann <[email protected]>
Cc: Takashi Iwai<[email protected]>
---

Kalle,

I marked this patch for V4.1, and I hope that timing can be met.

Thanks,

Larry
---

drivers/net/wireless/rtlwifi/usb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c
index 46ee956..27cd6ca 100644
--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -126,7 +126,7 @@ static int _usbctrl_vendorreq_sync_read(struct usb_device *udev, u8 request,

do {
status = usb_control_msg(udev, pipe, request, reqtype, value,
- index, pdata, len, 0); /*max. timeout*/
+ index, pdata, len, 1000);
if (status < 0) {
/* firmware download is checksumed, don't retry */
if ((value >= FW_8192C_START_ADDRESS &&
--
2.1.4

2015-04-28 10:56:00

by Kalle Valo

Subject: Re: [for,4.1] rtlwifi: rtl8192cu: Fix kernel deadlock

> The USB mini-driver in rtlwifi, which is used by rtl8192cu, issues a call to
> usb_control_msg() with a timeout value of 0. In some instances where the
> interface is shutting down, this infinite wait results in a CPU deadlock. A
> one second timeout fixes this problem without affecting any normal operations.
>
> This bug is reported at https://bugzilla.novell.com/show_bug.cgi?id=927786.
>
> Reported-by: Bernhard Wiedemann <[email protected]>
> Tested-by: Bernhard Wiedemann <[email protected]>
> Signed-off-by: Larry Finger <[email protected]>
> Cc: Stable <[email protected]>
> Cc: Bernhard Wiedemann <[email protected]>
> Cc: Takashi Iwai<[email protected]>

Thanks, applied to wireless-drivers.git.

Kalle Valo