diff options
author | Jerome Brunet <jbrunet@baylibre.com> | 2020-10-19 20:07:02 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-28 15:20:21 +0300 |
commit | 38203b8385bf6283537162bde7d499f830964711 (patch) | |
tree | a186fcc177e11d6f2da90355d5ffb97daeb5c739 /drivers/usb/class/cdc-acm.c | |
parent | 3cd54a618834430a26a648d880dd83d740f2ae30 (diff) | |
download | linux-38203b8385bf6283537162bde7d499f830964711.tar.xz |
usb: cdc-acm: fix cooldown mechanism
Commit a4e7279cd1d1 ("cdc-acm: introduce a cool down") is causing
regression if there is some USB error, such as -EPROTO.
This has been reported on some samples of the Odroid-N2 using the Combee II
Zibgee USB dongle.
> struct acm *acm = container_of(work, struct acm, work)
is incorrect in case of a delayed work and causes warnings, usually from
the workqueue:
> WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:1474 __queue_work+0x480/0x528.
When this happens, USB eventually stops working completely after a while.
Also the ACM_ERROR_DELAY bit is never set, so the cooldown mechanism
previously introduced cannot be triggered and acm_submit_read_urb() is
never called.
This changes makes the cdc-acm driver use a single delayed work, fixing the
pointer arithmetic in acm_softint() and set the ACM_ERROR_DELAY when the
cooldown mechanism appear to be needed.
Fixes: a4e7279cd1d1 ("cdc-acm: introduce a cool down")
Cc: Oliver Neukum <oneukum@suse.com>
Reported-by: Pascal Vizeli <pascal.vizeli@nabucasa.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201019170702.150534-1-jbrunet@baylibre.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class/cdc-acm.c')
-rw-r--r-- | drivers/usb/class/cdc-acm.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 30ef946a8e1a..1e7568867910 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -508,6 +508,7 @@ static void acm_read_bulk_callback(struct urb *urb) "%s - cooling babbling device\n", __func__); usb_mark_last_busy(acm->dev); set_bit(rb->index, &acm->urbs_in_error_delay); + set_bit(ACM_ERROR_DELAY, &acm->flags); cooldown = true; break; default: @@ -533,7 +534,7 @@ static void acm_read_bulk_callback(struct urb *urb) if (stopped || stalled || cooldown) { if (stalled) - schedule_work(&acm->work); + schedule_delayed_work(&acm->dwork, 0); else if (cooldown) schedule_delayed_work(&acm->dwork, HZ / 2); return; @@ -563,13 +564,13 @@ static void acm_write_bulk(struct urb *urb) acm_write_done(acm, wb); spin_unlock_irqrestore(&acm->write_lock, flags); set_bit(EVENT_TTY_WAKEUP, &acm->flags); - schedule_work(&acm->work); + schedule_delayed_work(&acm->dwork, 0); } static void acm_softint(struct work_struct *work) { int i; - struct acm *acm = container_of(work, struct acm, work); + struct acm *acm = container_of(work, struct acm, dwork.work); if (test_bit(EVENT_RX_STALL, &acm->flags)) { smp_mb(); /* against acm_suspend() */ @@ -585,7 +586,7 @@ static void acm_softint(struct work_struct *work) if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) { for (i = 0; i < acm->rx_buflimit; i++) if (test_and_clear_bit(i, &acm->urbs_in_error_delay)) - acm_submit_read_urb(acm, i, GFP_NOIO); + acm_submit_read_urb(acm, i, GFP_KERNEL); } if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags)) @@ -1351,7 +1352,6 @@ made_compressed_probe: acm->ctrlsize = ctrlsize; acm->readsize = readsize; acm->rx_buflimit = num_rx_buf; - INIT_WORK(&acm->work, acm_softint); INIT_DELAYED_WORK(&acm->dwork, acm_softint); init_waitqueue_head(&acm->wioctl); spin_lock_init(&acm->write_lock); @@ -1561,7 +1561,6 @@ static void acm_disconnect(struct usb_interface *intf) } acm_kill_urbs(acm); - cancel_work_sync(&acm->work); cancel_delayed_work_sync(&acm->dwork); tty_unregister_device(acm_tty_driver, acm->minor); @@ -1604,7 +1603,6 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message) return 0; acm_kill_urbs(acm); - cancel_work_sync(&acm->work); cancel_delayed_work_sync(&acm->dwork); acm->urbs_in_error_delay = 0; |