From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Ralph Siemsen <ralph.siemsen@linaro.org>
Cc: Peter Chen <peter.chen@kernel.org>,
Pawel Laszczak <pawell@cadence.com>,
Roger Quadros <rogerq@kernel.org>,
Aswath Govindraju <a-govindraju@ti.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Felipe Balbi <felipe.balbi@linux.intel.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
stable@vger.kernel.org
Subject: Re: [PATCH v2] usb: cdns3: Fix deadlock when using NCM gadget
Date: Wed, 19 Mar 2025 06:56:53 +0100 [thread overview]
Message-ID: <20250319055653.uSl-FEiQ@linutronix.de> (raw)
In-Reply-To: <20250318-rfs-cdns3-deadlock-v2-1-bfd9cfcee732@linaro.org>
On 2025-03-18 11:09:32 [-0400], Ralph Siemsen wrote:
> 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@vger.kernel.org
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Sebastian
prev parent reply other threads:[~2025-03-19 5:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-18 15:09 [PATCH v2] usb: cdns3: Fix deadlock when using NCM gadget Ralph Siemsen
2025-03-19 1:27 ` Peter Chen (CIX)
2025-03-19 5:56 ` Sebastian Andrzej Siewior [this message]
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