From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0AD4282C60; Tue, 29 Apr 2025 17:01:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745946114; cv=none; b=r/gtXZ89ozHG2WFTb16y3fxGqkMWT1gOnw9P1RCDVrkNiq6t3iBVl5Fa9oaelgINmRioU6gOVhKDrLPOcwvsKihizXX29Huw8IZkCYx3CNAn1zbWh/w3PiR+sWA6HQONuG3hItp4mqckePJXQHbQsgAQuKxtgvBkdrt8ip2oqbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745946114; c=relaxed/simple; bh=qtTh5sAPpqOr74OhPJi1PFIwvpg5UwU1zlm+WpLVXj8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FvdxiBxfYzI/CdfrkEtrYKtlaef9RGWqaFwLfqkTjCn+JCKERkvoTHmISLL7fVi3cywrbUAF0qfIYKd3n+aZn25BpIGEEtjUDZy7YG65Y/AlEOxO37/0OHHs4LEUOzd4rfMVyYQ7Xkwx0KRKQtIC/g9H+N7Esn+hO+lqzU0MaqQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wiRKogrv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wiRKogrv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41521C4CEE3; Tue, 29 Apr 2025 17:01:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745946113; bh=qtTh5sAPpqOr74OhPJi1PFIwvpg5UwU1zlm+WpLVXj8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wiRKogrvpCct6hXdgwRWPM77YJJAwfheX1tcv4cu3+ZBsM8htKZGrgfKmjCCBcqwO O+d+dL68R4V0OkVNiWF8xb8XMx1vmrwYCeLogJ+KKkwDsj+zuDDsGM84dvdHe7H0fo bRGVVjmjXXXzP8KvboMs7mlA/MtD1+2xzBnkJAFU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Ralph Siemsen , Peter Chen , Sebastian Andrzej Siewior Subject: [PATCH 6.14 160/311] usb: cdns3: Fix deadlock when using NCM gadget Date: Tue, 29 Apr 2025 18:39:57 +0200 Message-ID: <20250429161127.592228977@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161121.011111832@linuxfoundation.org> References: <20250429161121.011111832@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ralph Siemsen 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 Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") Signed-off-by: Ralph Siemsen Acked-by: Peter Chen Reviewed-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250318-rfs-cdns3-deadlock-v2-1-bfd9cfcee732@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/cdns3/cdns3-gadget.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1963,6 +1963,7 @@ static irqreturn_t cdns3_device_thread_i 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_i irqend: writel(~0, &priv_dev->regs->ep_ien); spin_unlock_irqrestore(&priv_dev->lock, flags); + local_bh_enable(); return ret; }