diff options
| author | Ralph Siemsen <ralph.siemsen@linaro.org> | 2025-03-18 11:09:32 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:59:12 +0200 |
| commit | 74cd6e408a4c010e404832f0e4609d29bf1d0c41 (patch) | |
| tree | 29f0fd5ed8158a74bafeeb9788cf5af71e205f0a | |
| parent | bce3055b08e303e28a8751f6073066f5c33a0744 (diff) | |
usb: cdns3: Fix deadlock when using NCM gadget
commit a1059896f2bfdcebcdc7153c3be2307ea319501f upstream.
The cdns3 driver has the same NCM deadlock as fixed in cdnsp by commit
58f2fcb3a845 ("usb: cdnsp: Fix deadlock issue during using NCM gadget").
Under PREEMPT_RT the deadlock can be readily triggered by heavy network
traffic, for example using "iperf --bidir" over NCM ethernet link.
The deadlock occurs because the threaded interrupt handler gets
preempted by a softirq, but both are protected by the same spinlock.
Prevent deadlock by disabling softirq during threaded irq handler.
Cc: stable <stable@kernel.org>
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250318-rfs-cdns3-deadlock-v2-1-bfd9cfcee732@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/cdns3/cdns3-gadget.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index fd1beb10bba7..19101ff1cf1b 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1963,6 +1963,7 @@ static irqreturn_t cdns3_device_thread_irq_handler(int irq, void *data) unsigned int bit; unsigned long reg; + local_bh_disable(); spin_lock_irqsave(&priv_dev->lock, flags); reg = readl(&priv_dev->regs->usb_ists); @@ -2004,6 +2005,7 @@ static irqreturn_t cdns3_device_thread_irq_handler(int irq, void *data) irqend: writel(~0, &priv_dev->regs->ep_ien); spin_unlock_irqrestore(&priv_dev->lock, flags); + local_bh_enable(); return ret; } |