Re: 5.9.11 still hanging 2mn at each boot and looping on nvidia-gpu 0000:01:00.3: PME# enabled (Quadro RTX 4000 Mobile)

From: Bjorn Helgaas <helgaas@kernel.org>
To: Marc MERLIN <marc_nouveau@merlins.org>
Cc: nouveau@lists.freedesktop.org,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux PCI <linux-pci@vger.kernel.org>
Subject: Re: 5.9.11 still hanging 2mn at each boot and looping on nvidia-gpu 0000:01:00.3: PME# enabled (Quadro RTX 4000 Mobile)
Date: Thu, 28 Jan 2021 14:59:46 -0600	[thread overview]
Message-ID: <20210128205946.GA27855@bjorn-Precision-5520> (raw)
In-Reply-To: <20210127213300.GA3046575@bjorn-Precision-5520>

On Wed, Jan 27, 2021 at 03:33:02PM -0600, Bjorn Helgaas wrote:
> On Sat, Dec 26, 2020 at 03:12:09AM -0800, Marc MERLIN wrote:
> > This started with 5.5 and hasn't gotten better since then, despite
> > some reports I tried to send.
> > 
> > As per my previous message:
> > I have a Thinkpad P70 with hybrid graphics.
> > 01:00.0 VGA compatible controller: NVIDIA Corporation GM107GLM [Quadro M600M] (rev a2)
> > that one works fine, I can use i915 for the main screen, and nouveau to
> > display on the external ports (external ports are only wired to nvidia
> > chip, so it's impossible to use them without turning the nvidia chip
> > on).
> >  
> > I now got a newer P73 also with the same hybrid graphics (setup as such
> > in the bios). It runs fine with i915, and I don't need to use external
> > display with nouveau for now (it almost works, but I only see the mouse
> > cursor on the external screen, no window or anything else can get
> > displayed, very weird).
> > 01:00.0 VGA compatible controller: NVIDIA Corporation TU104GLM [Quadro RTX 4000 Mobile / Max-Q] (rev a1)
> >  
> > 
> > after boot, when it gets the right trigger (not sure which ones), it
> > loops on this evern 2 seconds, mostly forever.
> > 
> > I'm not sure if it's nouveau's fault or the kernel's PCI PME's fault, or something else.
> 
> IIUC there are basically two problems:
> 
>   1) A 2 minute delay during boot
>   2) Some sort of event every 2 seconds that kills your battery life
> 
> Your machine doesn't sound unusual, and I haven't seen a flood of
> similar reports, so maybe there's something unusual about your config.
> But I really don't have any guesses for either one.
> 
> It sounds like v5.5 worked fine and you first noticed the slow boot
> problem in v5.8.  We *could* try to bisect it, but I know that's a lot
> of work on your part.
> 
> Grasping for any ideas for the boot delay; could you boot with
> "initcall_debug" and collect your "lsmod" output?  I notice async_tx
> in some of your logs, but I have no idea what it is.  It's from
> crypto, so possibly somewhat unusual?

Another random thought: is there any chance the boot delay could be
related to crypto waiting for entropy?