Re: Patch "x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32" has been added to the 6.14-stable tree

Re: Patch "x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32" has been added to the 6.14-stable tree

[Mateusz Jończyk]

Dnia 29 kwietnia 2025 03:41:48 CEST, Sasha Levin <sashal@kernel.org> napisał/a:
>This is a note to let you know that I've just added the patch titled
>
>    x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32
>
>to the 6.14-stable tree which can be found at:
>    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
>The filename of the patch is:
>     x86-kconfig-make-config_pci_cnb20le_quirk-depend-on-.patch
>and it can be found in the queue-6.14 subdirectory.
>
>If you, or anyone else, feels it should not be added to the stable tree,
>please let <stable@vger.kernel.org> know about it.

Hello, 

I'd like to ask that this patch be dropped from the stable queues (for 6.14 and earlier kernels). It does not fix
anything important, it is just for convenience - to
hide this one option from amd64 kernel Kconfig.

Greetings, 

Mateusz

>
>
>
>commit 8cc03c8c367ced0228a5fbaec8c02274f11b2a38
>Author: Mateusz Jończyk <mat.jonczyk@o2.pl>
>Date:   Fri Mar 21 21:48:48 2025 +0100
>
>    x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32
>    
>    [ Upstream commit d9f87802676bb23b9425aea8ad95c76ad9b50c6e ]
>    
>    I was unable to find a good description of the ServerWorks CNB20LE
>    chipset. However, it was probably exclusively used with the Pentium III
>    processor (this CPU model was used in all references to it that I
>    found where the CPU model was provided: dmesgs in [1] and [2];
>    [3] page 2; [4]-[7]).
>    
>    As is widely known, the Pentium III processor did not support the 64-bit
>    mode, support for which was introduced by Intel a couple of years later.
>    So it is safe to assume that no systems with the CNB20LE chipset have
>    amd64 and the CONFIG_PCI_CNB20LE_QUIRK may now depend on X86_32.
>    
>    Additionally, I have determined that most computers with the CNB20LE
>    chipset did have ACPI support and this driver was inactive on them.
>    I have submitted a patch to remove this driver, but it was met with
>    resistance [8].
>    
>    [1] Jim Studt, Re: Problem with ServerWorks CNB20LE and lost interrupts
>        Linux Kernel Mailing List, https://lkml.org/lkml/2002/1/11/111
>    
>    [2] RedHat Bug 665109 - e100 problems on old Compaq Proliant DL320
>        https://bugzilla.redhat.com/show_bug.cgi?id=665109
>    
>    [3] R. Hughes-Jones, S. Dallison, G. Fairey, Performance Measurements on
>        Gigabit Ethernet NICs and Server Quality Motherboards,
>        http://datatag.web.cern.ch/papers/pfldnet2003-rhj.doc
>    
>    [4] "Hardware for Linux",
>        Probe #d6b5151873 of Intel STL2-bd A28808-302 Desktop Computer (STL2)
>        https://linux-hardware.org/?probe=d6b5151873
>    
>    [5] "Hardware for Linux", Probe #0b5d843f10 of Compaq ProLiant DL380
>        https://linux-hardware.org/?probe=0b5d843f10
>    
>    [6] Ubuntu Forums, Dell Poweredge 2400 - Adaptec SCSI Bus AIC-7880
>        https://ubuntuforums.org/showthread.php?t=1689552
>    
>    [7] Ira W. Snyder, "BISECTED: 2.6.35 (and -git) fail to boot: APIC problems"
>        https://lkml.org/lkml/2010/8/13/220
>    
>    [8] Bjorn Helgaas, "Re: [PATCH] x86/pci: drop ServerWorks / Broadcom
>        CNB20LE PCI host bridge driver"
>        https://lore.kernel.org/lkml/20220318165535.GA840063@bhelgaas/T/
>    
>    Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
>    Signed-off-by: David Heideberg <david@ixit.cz>
>    Signed-off-by: Ingo Molnar <mingo@kernel.org>
>    Cc: "H. Peter Anvin" <hpa@zytor.com>
>    Cc: Linus Torvalds <torvalds@linux-foundation.org>
>    Link: https://lore.kernel.org/r/20250321-x86_x2apic-v3-6-b0cbaa6fa338@ixit.cz
>    Signed-off-by: Sasha Levin <sashal@kernel.org>
>
>diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>index aeb95b6e55369..de47e7c435679 100644
>--- a/arch/x86/Kconfig
>+++ b/arch/x86/Kconfig
>@@ -2981,13 +2981,21 @@ config MMCONF_FAM10H
> 	depends on X86_64 && PCI_MMCONFIG && ACPI
> 
> config PCI_CNB20LE_QUIRK
>-	bool "Read CNB20LE Host Bridge Windows" if EXPERT
>-	depends on PCI
>+	bool "Read PCI host bridge windows from the CNB20LE chipset" if EXPERT
>+	depends on X86_32 && PCI
> 	help
> 	  Read the PCI windows out of the CNB20LE host bridge. This allows
> 	  PCI hotplug to work on systems with the CNB20LE chipset which do
> 	  not have ACPI.
> 
>+	  The ServerWorks (later Broadcom) CNB20LE was a chipset designed
>+	  most probably only for Pentium III.
>+
>+	  To find out if you have such a chipset, search for a PCI device with
>+	  1166:0009 PCI IDs, for example by executing
>+		lspci -nn | grep '1166:0009'
>+	  The code is inactive if there is none.
>+
> 	  There's no public spec for this chipset, and this functionality
> 	  is known to be incomplete.
> 

Re: Patch "x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32" has been added to the 6.14-stable tree

[Greg KH]

On Tue, Apr 29, 2025 at 07:38:25AM +0200, Mateusz Jończyk wrote:
> Dnia 29 kwietnia 2025 03:41:48 CEST, Sasha Levin <sashal@kernel.org> napisał/a:
> >This is a note to let you know that I've just added the patch titled
> >
> >    x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32
> >
> >to the 6.14-stable tree which can be found at:
> >    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> >
> >The filename of the patch is:
> >     x86-kconfig-make-config_pci_cnb20le_quirk-depend-on-.patch
> >and it can be found in the queue-6.14 subdirectory.
> >
> >If you, or anyone else, feels it should not be added to the stable tree,
> >please let <stable@vger.kernel.org> know about it.
> 
> Hello, 
> 
> I'd like to ask that this patch be dropped from the stable queues (for 6.14 and earlier kernels). It does not fix
> anything important, it is just for convenience - to
> hide this one option from amd64 kernel Kconfig.

Ok, now dropped from everywhere, thanks.

greg k-h