From: Mateusz Jończyk mat.jonczyk@o2.pl
[ 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 --- arch/x86/Kconfig | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0e27ebd7e36a9..a9746246f2d95 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2978,13 +2978,21 @@ 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.