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Date: Wed, 14 Feb 2024 14:19:19 -0800
From: Ira Weiny <ira.weiny@intel.com>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>, Steven Rostedt
	<rostedt@goodmis.org>
CC: Ira Weiny <ira.weiny@intel.com>, "Rafael J. Wysocki" <rafael@kernel.org>,
	Dan Williams <dan.j.williams@intel.com>, Smita Koralahalli
	<Smita.KoralahalliChannabasappa@amd.com>, <linux-acpi@vger.kernel.org>,
	<linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Dan Carpenter
	<dan.carpenter@linaro.org>, Masami Hiramatsu <mhiramat@kernel.org>, "Mathieu
 Desnoyers" <mathieu.desnoyers@efficios.com>,
	<linux-trace-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] acpi/ghes: Prevent sleeping with spinlock held
Message-ID: <65cd3c671cf86_d552e294dd@iweiny-mobl.notmuch>
References: <20240206-cxl-cper-smatch-v2-1-84ed07563c31@intel.com>
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 <20240214102310.7ba53f3a@gandalf.local.home>
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Jonathan Cameron wrote:
> On Wed, 14 Feb 2024 10:23:10 -0500
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
> > On Wed, 14 Feb 2024 12:11:53 +0000
> > Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:
> > 
> > > So I'm thinking this is a won't fix - wait for the printk rework to land and
> > > assume this will be resolved as well?  
> > 
> > That pretty much sums up what I was about to say ;-)
> > 
> > tp_printk is more of a hack and not to be used sparingly. With the right
> > trace events it can hang the machine.
> > 
> > So, you can use your internal patch locally, but I would recommend waiting
> > for the new printk changes to land.

Steven, Do you think that will land in 6.9?

> >
> > I'm really hoping that will be soon!
> > 
> > -- Steve
> 
> Thanks Steve,
> 
> Ira's fix is needed for other valid locking reasons - this was 'just another'
> lock debugging report that came up whilst testing it.
> 
> For this patch (not a potential additional one that we aren't going to do ;)
> 
> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Jonathan,

Again thanks for the testing!  However, Dan and I just discussed this and
he has an uneasy feeling about going forward with this for 6.8 final.

If we revert the following patch I can squash this fix and wait for the
tp_printk() fix to land in 6.9 and resubmit.

Dan here is the patch which backs out the actual bug:

	Fixes: 671a794c33c6 ("acpi/ghes: Process CXL Component Events") 

Thanks everyone,
Ira