linux-kernel - Re: [PATCH v9 6/9] PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <91b501c0ce92de681cc699eb6064840caad28803.camel@kernel.org>
Date: Fri, 06 Dec 2024 20:31:10 +0100
From: Niklas Schnelle <niks@...nel.org>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
	linux-pci@...r.kernel.org, Bjorn Helgaas <bhelgaas@...gle.com>, Lorenzo
 Pieralisi <lorenzo.pieralisi@....com>, Rob Herring <robh@...nel.org>,
 Krzysztof Wilczyński	 <kw@...ux.com>, "Maciej W . Rozycki"
 <macro@...am.me.uk>, Jonathan Cameron	 <Jonathan.Cameron@...wei.com>, Lukas
 Wunner <lukas@...ner.de>, Alexandru Gagniuc <mr.nuke.me@...il.com>, Krishna
 chaitanya chundru <quic_krichai@...cinc.com>, Srinivas Pandruvada
 <srinivas.pandruvada@...ux.intel.com>, "Rafael J . Wysocki"
 <rafael@...nel.org>, 	linux-pm@...r.kernel.org, Smita Koralahalli	
 <Smita.KoralahalliChannabasappa@....com>, linux-kernel@...r.kernel.org
Cc: Daniel Lezcano <daniel.lezcano@...aro.org>, Amit Kucheria
 <amitk@...nel.org>,  Zhang Rui <rui.zhang@...el.com>, Christophe JAILLET
 <christophe.jaillet@...adoo.fr>, niks@...nel.org
Subject: Re: [PATCH v9 6/9] PCI/bwctrl: Re-add BW notification portdrv as
 PCIe BW controller

On Fri, 2024-12-06 at 19:12 +0100, Niklas Schnelle wrote:
> On Fri, 2024-10-18 at 17:47 +0300, Ilpo Järvinen wrote:
> > This mostly reverts the commit b4c7d2076b4e ("PCI/LINK: Remove
> > bandwidth notification"). An upcoming commit extends this driver
> > building PCIe bandwidth controller on top of it.
> > 
> > The PCIe bandwidth notification were first added in the commit
> > e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth
> > notification") but later had to be removed. The significant changes
> > compared with the old bandwidth notification driver include:
> > 
---8<---
> > ---
> 
> Hi Ilpo,
> 
> I bisected a v6.13-rc1 boot hang on my personal workstation to this
> patch. Sadly I don't have much details like a panic or so because the
> boot hangs before any kernel messages, or at least they're not visible
> long enough to see. I haven't yet looked into the code as I wanted to
> raise awareness first. Since the commit doesn't revert cleanly on
> v6.13-rc1 I also haven't tried that yet.
> 
> Here are some details on my system:
> - AMD Ryzen 9 3900X 
> - ASRock X570 Creator Motherboard
> - Radeon RX 5600 XT
> - Intel JHL7540 Thunderbolt 3 USB Controller (only USB 2 plugged)
> - Intel 82599 10 Gigabit NIC with SR-IOV enabled with 2 VFs
> - Intel n I211 Gigabit NIC
> - Intel Wi-Fi 6 AX200
> - Aquantia AQtion AQC107 NIC
> 
> If you have patches or things to try just ask.
> 
> Thanks,
> Niklas
> 

Ok I can now at least confirm that bluntly disabling the new bwctrl
driver with the below diff on top of v6.13-rc1 circumvents the boot
hang I'm seeing. So it's definitely this.

diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
index 5e10306b6308..6fa54480444a 100644
--- a/drivers/pci/pcie/portdrv.c
+++ b/drivers/pci/pcie/portdrv.c
@@ -828,7 +828,7 @@ static void __init pcie_init_services(void)
        pcie_aer_init();
        pcie_pme_init();
        pcie_dpc_init();
-       pcie_bwctrl_init();
+       /* pcie_bwctrl_init(); */
        pcie_hp_init();
 }