On Wed, 2016-04-27 at 01:02 +0200, Ben Hutchings wrote:
> 3.16.35-rc1 review patch. If anyone has any objections, please let me know.
Also dropping this from 3.16-longterm.
Ben.
> ------------------
>
> 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: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> ---
> 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
> @@ -137,10 +137,14 @@ 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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--
Ben Hutchings
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