mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Ali Tariq <alitariq45892@gmail.com>
To: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>,
	netdev@vger.kernel.org, Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Yixun Lan <dlan@kernel.org>,
	Vivian Wang <wangruikang@iscas.ac.cn>,
	Chukun Pan <amadeus@jmu.edu.cn>,
	Siddharth Vadapalli <s-vadapalli@ti.com>,
	Tomas Hlavacek <tmshlvck@gmail.com>,
	Muhammad Bilal <meatuni001@gmail.com>,
	Maxime Chevallier <maxime.chevallier@bootlin.com>,
	linux-riscv@lists.infradead.org, spacemit@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] net: spacemit: Hold RTNL lock in emac_resume() and emac_suspend()
Date: Fri, 6 Nov 2026 15:44:50 +0500	[thread overview]
Message-ID: <c55c5878-d9c1-4863-bc55-99d334ba2ede@gmail.com> (raw)
In-Reply-To: <DMO13SWAGZAN.NYISGLGI7Y5A@linux.spacemit.com>



On 11/6/26 2:43 PM, Troy Mitchell wrote:
> On Thu,  5 Nov 2026 17:34:37 +0500, Ali Tariq wrote:
>> @@ -2056,7 +2059,9 @@ static int emac_suspend(struct device *dev)
>>   		return 0;
>>   	}
>>   
>> +	rtnl_lock();
>>   	emac_stop(ndev);
>> +	rtnl_unlock();
>>   
>>   	clk_disable_unprepare(priv->bus_clk);
>>   	netif_device_detach(ndev);
> This can deadlock. emac_stop() -> emac_down() calls
> cancel_work_sync(&priv->tx_timeout_task) with RTNL now held, while
> emac_tx_timeout_task() starts with rtnl_lock().
> 

Thanks Troy, that makes sense.

For the deadlock, I think the correct function to call is rtnl_trylock() 
inside the emac_tx_timeout_task(), which would return if the lock is 
already held and will hold the lock if it is not.

What are your thoughts on this? Does a v2 changing rtnl_lock() to 
rtnl_trylock() inside emac_tx_timeout_task() make sense?

Regards,
Ali

  reply	other threads:[~2026-11-06 10:45 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-05 12:34 Ali Tariq
2026-11-05 13:40 ` Breno Leitao
2026-11-05 22:28   ` Vadim Fedorenko
2026-11-06  9:41     ` Troy Mitchell
2026-11-06 11:54       ` Breno Leitao
2026-11-06 14:28         ` Troy Mitchell
2026-11-06  9:43 ` Troy Mitchell
2026-11-06 10:44   ` Ali Tariq [this message]
2026-11-06 14:26     ` Troy Mitchell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c55c5878-d9c1-4863-bc55-99d334ba2ede@gmail.com \
    --to=alitariq45892@gmail.com \
    --cc=amadeus@jmu.edu.cn \
    --cc=andrew+netdev@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=dlan@kernel.org \
    --cc=edumazet@kernel.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=maxime.chevallier@bootlin.com \
    --cc=meatuni001@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=s-vadapalli@ti.com \
    --cc=spacemit@lists.linux.dev \
    --cc=tmshlvck@gmail.com \
    --cc=troy.mitchell@linux.spacemit.com \
    --cc=vadim.fedorenko@linux.dev \
    --cc=wangruikang@iscas.ac.cn \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®