diff mbox series

f_midi_complete to call tasklet_hi_schedule

Message ID CAArt=Lh0S6UPX0OAhudTWxE7g7xbukQqHmuDAwCDwjBUbuJUnw@mail.gmail.com (mailing list archive)
State Superseded
Headers show
Series f_midi_complete to call tasklet_hi_schedule | expand

Commit Message

Jill Donahue Feb. 6, 2025, 7:23 p.m. UTC 
From 9cb2628740d9f55f6f3faa5cce2de5eb8590f434 Mon Sep 17 00:00:00 2001
From: Jill Donahue <jilliandonahue58@gmail.com>
Date: Thu, 6 Feb 2025 10:18:05 -0700
Subject: [PATCH] f_midi_complete to call tasklet_hi_schedule

When using USB MIDI, a lock is attempted to be acquired twice through a
re-entrant call to f_midi_transmit, causing a deadlock.

Fix it by using tasklet_hi_schedule() to schedule the inner
f_midi_transmit() via a tasklet from the completion handler.

Link: https://lore.kernel.org/all/CAArt=LjxU0fUZOj06X+5tkeGT+6RbXzpWg1h4t4Fwa_KGVAX6g@mail.gmail>

Fixes: d5daf49b58661 ("USB: gadget: midi: add midi function driver")
Signed-off-by: Jill Donahue <jilliandonahue58@gmail.com>
---
 drivers/usb/gadget/function/f_midi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jill Donahue Feb. 6, 2025, 7:36 p.m. UTC | #1 
Sent with a broken link, my mistake

On Thu, Feb 6, 2025 at 12:23 PM Jillian Donahue
<jilliandonahue58@gmail.com> wrote:
>
> From 9cb2628740d9f55f6f3faa5cce2de5eb8590f434 Mon Sep 17 00:00:00 2001
> From: Jill Donahue <jilliandonahue58@gmail.com>
> Date: Thu, 6 Feb 2025 10:18:05 -0700
> Subject: [PATCH] f_midi_complete to call tasklet_hi_schedule
>
> When using USB MIDI, a lock is attempted to be acquired twice through a
> re-entrant call to f_midi_transmit, causing a deadlock.
>
> Fix it by using tasklet_hi_schedule() to schedule the inner
> f_midi_transmit() via a tasklet from the completion handler.
>
> Link: https://lore.kernel.org/all/CAArt=LjxU0fUZOj06X+5tkeGT+6RbXzpWg1h4t4Fwa_KGVAX6g@mail.gmail>
>
> Fixes: d5daf49b58661 ("USB: gadget: midi: add midi function driver")
> Signed-off-by: Jill Donahue <jilliandonahue58@gmail.com>
> ---
>  drivers/usb/gadget/function/f_midi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/function/f_midi.c
> b/drivers/usb/gadget/function/f_midi.c
> index 837fcdfa3..37d438e5d 100644
> --- a/drivers/usb/gadget/function/f_midi.c
> +++ b/drivers/usb/gadget/function/f_midi.c
> @@ -283,7 +283,7 @@ f_midi_complete(struct usb_ep *ep, struct usb_request *req)
>                         /* Our transmit completed. See if there's more to go.
>                          * f_midi_transmit eats req, don't queue it again. */
>                         req->length = 0;
> -                       f_midi_transmit(midi);
> +                       tasklet_hi_schedule(&midi->tasklet);
>                         return;
>                 }
>                 break;
> --
> 2.25.1
diff mbox series

Patch

diff --git a/drivers/usb/gadget/function/f_midi.c
b/drivers/usb/gadget/function/f_midi.c
index 837fcdfa3..37d438e5d 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -283,7 +283,7 @@  f_midi_complete(struct usb_ep *ep, struct usb_request *req)
                        /* Our transmit completed. See if there's more to go.
                         * f_midi_transmit eats req, don't queue it again. */
                        req->length = 0;
-                       f_midi_transmit(midi);
+                       tasklet_hi_schedule(&midi->tasklet);
                        return;
                }
                break;