From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.250 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793917716; b=KrWHy/i0nnqF0gli3iFlSowEXj/b7vvgVnPlW8Zjmt54E5GKsCraWQh1Pa19+BpVv3fr fF712chwf4UkM6Yr8hVWdAPdyW6PHzJZvkq3IeZRWOG3JYuXQDrWr5g6pyreMzZqfzXQV Eq0gvGHErKB5AqAPfol+b+yAlat/GS7m9BXRJq/MhL2k8XFjUkfgdek6efllgRWrBee/6 8iL4HiAsyNnESBLnBe7lI77dnx4lk0RhXBmTmCtkvEXJ+uAzt2cnJ5OVQJ/qTdS5JzIQ5 mUHI2dx5+7mgjTnK+zyxPa+nRbfjRgvlnkSr5EZr3XC4tgXHb8V23fwSP6tK4CyJvXg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793917716; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=teFZI5ZT0tF3baaZ5GsOyIljCJ7tSwWYOvxyzPD92zg=; b=hPxFREOAXJ2JWW+77XWdJwAf25tpPS2eYGF8s275uzqdUAEwi5rxcq5lAa8X6NRq0Njl OcqfJFCXejgXQvhWMdTu0athwuwP+dfZDYfjevCs1Klv4LTGgQYbuHxipP0C9/Gtlrxbj 0W62d6GXd5NLGlPOjC6rqYo1QIbgwnkWWvCAjjbj9Ohms8ulJ/xOEwGOrQlzJKoP480IW eFr5gCoSriGzM6znc3nj+BaKOD4Oip8TbLUMQftaOsluq+gC1IuWo9XjBd6iPh9V7HMd1 wjX2BIXKqPg7k17Hs+nNEkJYOG7wLsVgGPm1c+/w9m9AUeSGdSmU6zK1MNPcdl23Odg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=k7n7M399; arc=none smtp.remote-ip=95.215.58.250 Received: from mta1.migadu.com (out-250.mta1.migadu.com [95.215.58.250]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2D2C606A326 for ; Thu, 5 Nov 2026 22:28:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org F2D2C606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=k7n7M399 X-Envelope-To: netdev@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=RMLKgoqWLv73HkP/fp6tsjHhZlyH0aziusIjVEhYzLc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793917714; v=1; x=1794522514; b=k7n7M399r7CdMfhJhF/pQNTZZqYvtpZ5ydqHsfEf5gRKfF0w1BwoyoTUp8hvxCpvWS/4D3Rf i1fTkZZUMvgSHD0rDEzCJjgyyMjFBfe+ITXArBI7XdY9xiOjdkRFyAR52IKEFBXRgiCAvjQwjzK AoklpAN/HvcQSj5OTb4mFcLY= X-Envelope-To: netdev@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 8774a739f2d0ed26; Thu, 05 Nov 2026 22:28:33 +0000 X-Mizu-Trace-ID: 8774a739f2d0ed26 X-Migadu-Flow: FLOW_OUT Message-ID: <6c36ec6d-5bc8-4ac3-8ad0-79eac7873b67@linux.dev> Date: Thu, 5 Nov 2026 23:28:31 +0100 X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net] net: spacemit: Hold RTNL lock in emac_resume() and emac_suspend() To: Breno Leitao , Ali Tariq Cc: netdev@vger.kernel.org, Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Yixun Lan , Troy Mitchell , Vivian Wang , Chukun Pan , Siddharth Vadapalli , Tomas Hlavacek , Muhammad Bilal , Maxime Chevallier , "open list:RISC-V SPACEMIT SoC Support" , "open list:RISC-V SPACEMIT SoC Support" , open list References: <20261105123441.2524171-1-alitariq45892@gmail.com> Content-Language: en-US From: Vadim Fedorenko In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 05/11/2026 13:40, Breno Leitao wrote: > On Thu, Nov 05, 2026 at 05:34:37PM +0500, Ali Tariq wrote: >> The emac_resume() calls the emac_open() and emac_suspend() calls >> emac_stop() functions directly without holding the lock through >> rtnl_lock(). These functions rely on phy_disconnect() which reads pointer >> with rtnl_dereference(). But since no lock is being held, >> rtnl_dereference throws a suspicious RCU usage on >> Orange Pi RV2 (SpacemiT K1) warning when lockdep is enabled. >> >> WARNING: suspicious RCU usage >> drivers/net/phy/phy_device.c:1831 suspicious rcu_dereference_protected() usage! >> Call Trace: >> phy_detach_internal+0x490/0x5f2 >> phy_disconnect+0x90/0xc0 >> emac_stop+0x114/0x626 >> emac_suspend+0xac/0x126 >> platform_pm_suspend+0x72/0xe4 >> >> Hold RTNL lock before emac_open() and emac_stop() with rtnl_lock() and >> release the lock when functions return with rtnl_unlock(). > > This would work, but I am wondering if it would be possible to call rtnl > inside the _open function, when dealing with the PHY? in other words, > shrink the time rtnl is held. +1, especially in emac_open() rtnl is needed only in error path case