4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
commit 4fccb0767fdbdb781a9c5b5c15ee7b219443c89d upstream.
This patch fixes an issue that usbhsg_queue_done() may cause kernel
panic when dma callback is running and usb_ep_disable() is called
by interrupt handler. (Especially, we can reproduce this issue using
g_audio with usb-dmac driver.)
For example of a flow:
usbhsf_dma_complete (on tasklet)
--> usbhsf_pkt_handler (on tasklet)
--> usbhsg_queue_done (on tasklet)
*** interrupt happened and usb_ep_disable() is called ***
--> usbhsg_queue_pop (on tasklet)
Then, oops happened.
Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/renesas_usbhs/mod_gadget.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/usb/renesas_usbhs/mod_gadget.c
+++ b/drivers/usb/renesas_usbhs/mod_gadget.c
@@ -158,10 +158,14 @@ static void usbhsg_queue_done(struct usb
struct usbhs_pipe *pipe = pkt->pipe;
struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe);
struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
+ unsigned long flags;
ureq->req.actual = pkt->actual;
- usbhsg_queue_pop(uep, ureq, 0);
+ usbhs_lock(priv, flags);
+ if (uep)
+ __usbhsg_queue_pop(uep, ureq, 0);
+ usbhs_unlock(priv, flags);
}
static void usbhsg_queue_push(struct usbhsg_uep *uep,
--
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