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From: Matt Fleming <matt@readmodwrite.com>
To: Corey Minyard <corey@minyard.net>
Cc: Tony Camuso <tcamuso@redhat.com>,
	 openipmi-developer@lists.sourceforge.net,
	linux-kernel@vger.kernel.org, kernel-team@cloudflare.com,
	 Matt Fleming <mfleming@cloudflare.com>,
	Frederick Lawler <fred@cloudflare.com>
Subject: Re: [PATCH] ipmi: Add timeout to unconditional wait in __get_device_id()
Date: Sun, 19 Apr 2026 21:50:38 +0100	[thread overview]
Message-ID: <aeUsnI2nHAbtqoqt@matt-Precision-5490> (raw)
In-Reply-To: <aeLIE0Psdlvr9l7j@mail.minyard.net>

On Fri, Apr 17, 2026 at 06:53:55PM -0500, Corey Minyard wrote:
> 
> The EVENT_MSG_BUFFER_FULL flag only gets cleared when a unsuccessful
> READ_EVENT_MSG_BUFFER command completes.  Getting data from the
> BMC has higher priority than sending data to the BMC.
> 
> If the BMC continually reports success from READ_EVENT_MSG_BUFFER, then
> that would certainly wedge the driver.  But it would have to continually
> report success for that command, which would be strange as its supposed
> to error out when the queue is empty.
 
That does indeed appear to be what's happening.

The implementation of intel-ipmi-oem's OpenBMC READ_EVENT_MSG_BUFFER
handler does not fail when there is nothing to read,

  https://github.com/openbmc/intel-ipmi-oem/blob/master/src/bridgingcommands.cpp#L704

> If it's really something like that, I could also look at adding limits
> for those operations.

That would be great. Me and Fred would be happy to test out any patch.

I still think the original patch I sent is a worthwhile defense.

Our periodic monitoring scripts cause TASK_UNINTERRUPTIBLE tasks to
block behind one another when we hit these kinds of issues in the IPMI
code. Untangling that across thousands of machines can be time
consuming and a more explicit EIO or ETIMEDOUT would help with triage.

  reply	other threads:[~2026-04-19 20:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-15 11:59 Matt Fleming
2026-04-15 12:16 ` Corey Minyard
2026-04-15 15:46   ` Tony Camuso
2026-04-15 21:22     ` Frederick Lawler
2026-04-16 14:28       ` Tony Camuso
2026-04-17 16:01         ` Matt Fleming
2026-04-17 15:41   ` Matt Fleming
2026-04-17 22:23   ` Matt Fleming
2026-04-17 23:53     ` Corey Minyard
2026-04-19 20:50       ` Matt Fleming [this message]
2026-04-20 16:33         ` Corey Minyard
2026-04-20 18:11           ` Corey Minyard

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