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 54943245007; Tue, 29 Apr 2025 17:22:15 +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=1745947335; cv=none; b=o3lwBnY78Iiz9C0kXJcW3Pq8ADeeZ2nz5gtJwzn2CXiI91HQc5kfxYkUS5bRW4eiLMbXTAuP6ew85EsOLemYtFiWqu3pM66nPCcG2NjYP5iumTQMKDTpnYm5NOb4TNdMPRYDaHHoT7ZdVY+ICqPI0mdNa6YLvL5YYlIlFqZCkXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745947335; c=relaxed/simple; bh=PyhcafT2aeN8peGpOob+ooSIsnWn46ZcjLD3M/Z0N64=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cltxh1qmEgbLkrQmNjGHQuglDibba110Cw+VgH4E5dFRf76Ofq8P/eWg7pwhZjjTItpMoGR2J4+8zeV4dU5tVXdkjE3ZRwvuZXGmaLP7/7jqhb6RV/Cbf7kZ6ty2m6xJ6PAq6bggTkO7vbmSibm8AvZh5ID6ygkrBngCmGNQBFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MVzNZZ/J; 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="MVzNZZ/J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1969C4CEE3; Tue, 29 Apr 2025 17:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745947335; bh=PyhcafT2aeN8peGpOob+ooSIsnWn46ZcjLD3M/Z0N64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MVzNZZ/J86BUTk5B4UupE6iUYSwdz8Vg2ZPcUzMKDO+6E0hHvIiFkskSOZ0FYBAji 1EWPkUAdeawhNUMFUavU4VCMO79EEBMMKC4ynMZoarNmXvD5V2fS9BK6rvEVNnLLnt kcuomSnn4A2ciUEADJ0VVzRLzsgyYNdhIUerdIvQ= 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 5.10 247/286] usb: cdns3: Fix deadlock when using NCM gadget Date: Tue, 29 Apr 2025 18:42:31 +0200 Message-ID: <20250429161118.089752730@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161107.848008295@linuxfoundation.org> References: <20250429161107.848008295@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-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/gadget.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/usb/cdns3/gadget.c +++ b/drivers/usb/cdns3/gadget.c @@ -1961,6 +1961,7 @@ 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); @@ -2002,6 +2003,7 @@ 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; }