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From: Jacob Keller <jacob.e.keller@intel.com>
To: Jakub Kicinski <kuba@kernel.org>, Rosen Penev <rosenp@gmail.com>
Cc: <netdev@vger.kernel.org>, Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	"Paolo Abeni" <pabeni@redhat.com>, Jeff Garzik <jeff@garzik.org>,
	Roland Dreier <rdreier@cisco.com>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net] net: ibm: emac: mal: fix potential system hang in mal_remove()
Date: Mon, 8 Jun 2026 18:13:55 -0700	[thread overview]
Message-ID: <4575ae96-2084-4f96-8260-5025fd1ea7f5@intel.com> (raw)
In-Reply-To: <20260608173638.74da73fe@kernel.org>

On 6/8/2026 5:36 PM, Jakub Kicinski wrote:
> On Thu, 4 Jun 2026 16:03:43 -0700 Rosen Penev wrote:
>>>> -     if (!list_empty(&mal->list))
>>>> +     if (!list_empty(&mal->list)) {
>>>> +             napi_disable(&mal->napi);
>>>>               /* This is *very* bad */
>>>>               WARN(1, KERN_EMERG
>>>>                      "mal%d: commac list is not empty on remove!\n",
>>>>                      mal->index);  
>>>
>>> This one doesn't make sense to me. The list_empty check does a WARN()
>>> indicating that this is not supposed to happen.
>>>
>>> This implies that list_empty should be true, otherwise we'd see a WARN
>>> every time mal_remove is called.
>>>
>>> But in that case, we'd have been calling napi_disable incorrectly in
>>> most cases where it was previously unsafe according to your claim.
>>>
>>> At best, this list_empty check is the wrong way to tell if the napi is
>>> disabled, at worst, this whole change is pointless.  
>> I asked the AI. It doesn't agree:
> 
> FTR I agree with Jake, the patch seems to indicate bigger structural
> issues. Then again I don't want to encourage the stream of patches
> to this driver so let me just apply this..

I don't see how applying this discourages the stream of patches?
Wouldn't that be encouraging?

Or I guess the patch "does" fix something (an extra call to
napi_disable) and you don't want to encourage a raff of future changes
to try and fix the overall structural issues? I guess that makes sense.

I still don't follow how this fixes

  parent reply	other threads:[~2026-06-09  1:14 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-03 23:08 [PATCH net] net: ibm: emac: mal: fix potential system hang in mal_remove() Rosen Penev
2026-06-04 18:52 ` Jacob Keller
2026-06-04 23:03   ` Rosen Penev
2026-06-09  0:36     ` Jakub Kicinski
2026-06-09  1:13       ` Jacob Keller
2026-06-09  1:13       ` Jacob Keller [this message]
2026-06-09  1:51         ` Rosen Penev
2026-06-09  0:40 ` patchwork-bot+netdevbpf

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