From: "Taedcke, Christian" <christian.taedcke-oss@weidmueller.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
christian.taedcke@weidmueller.com
Cc: "Théo Lebrun" <theo.lebrun@bootlin.com>,
"Conor Dooley" <conor.dooley@microchip.com>,
"Andrew Lunn" <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Kevin Hao" <haokexin@gmail.com>,
"Simon Horman" <horms@kernel.org>,
"Clark Williams" <clrkwllms@kernel.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Robert Hancock" <robert.hancock@calian.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev, stable@vger.kernel.org
Subject: Re: [PATCH net 2/2] net: macb: mask TXUBR during TX NAPI poll to prevent IRQ storms
Date: Tue, 7 Jul 2026 15:41:00 +0200 [thread overview]
Message-ID: <389f9c70-a2d1-4d6d-9c36-b875f896629e@weidmueller.com> (raw)
In-Reply-To: <20260706150552.EomovsBn@linutronix.de>
On 7/6/2026 5:05 PM, Sebastian Andrzej Siewior wrote:
> On 2026-07-06 16:02:15 [+0200], Christian Taedcke via B4 Relay wrote:
>> From: Christian Taedcke <christian.taedcke@weidmueller.com>
>>
>> macb_interrupt() defers TX completion handling to NAPI, but when it
>> schedules the poll it only masks TCOMP, even though TXUBR is enabled
>> alongside it (both are part of MACB_TX_INT_FLAGS). macb_tx_poll() is
>> asymmetric in the same way and only re-enables TCOMP. TXUBR is thus
>> left unmasked while responsibility for handling it has been deferred
>> to NAPI.
>
> So this is not a race condition, this is always a failure?
As far as in understand it: yes
>
> Sebastian
Christian
prev parent reply other threads:[~2026-07-07 13:41 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-06 14:02 [PATCH net 0/2] net: macb: fix TXUBR interrupt storm on link flapping Christian Taedcke via B4 Relay
2026-07-06 14:02 ` [PATCH net 1/2] net: macb: reprogram TBQP after shuffling the TX ring on link-up Christian Taedcke via B4 Relay
2026-07-06 15:04 ` Sebastian Andrzej Siewior
2026-07-07 13:36 ` Taedcke, Christian
2026-07-07 9:13 ` Kevin Hao
2026-07-07 14:29 ` Taedcke, Christian
2026-07-08 3:05 ` Kevin Hao
2026-07-06 14:02 ` [PATCH net 2/2] net: macb: mask TXUBR during TX NAPI poll to prevent IRQ storms Christian Taedcke via B4 Relay
2026-07-06 15:05 ` Sebastian Andrzej Siewior
2026-07-07 13:41 ` Taedcke, Christian [this message]
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