[elrepo] [el5 kernel] NIC and XHCI for Kaby Lake: feasibility

[Phil Perry]

On 28/12/16 19:05, Björn Gerhart wrote:
> Hi folks,
>
> a customer wants to keep his CentOS5 installation, but at the same time
> change the hardware platform to Skylake (in particular even Kaby Lake).
>
> As X is not used anyway, the graphic chipset support fortunately is not
> relevant.
>
> But USB support is required: With this chipset, the USB3 host adapter
> can not run in USB2 emulation mode any more. As I understand, this means
> that the xhci_hcd module would be needed to operate USB devices. The el5
> kernel does not provide that module.
>
> Furthermore, the Intel NIC device 15b8 ("Ethernet Connection (2)
> I219-V") is required. Following Intel's history, the e1000e driver
> received support for it in October 2015. The latest el5 package
> therefore is kmod-e1000e-3.1.0.2-1.el5.elrepo.i686.rpm from August 2015.
> With this module loaded, eth0 is not getting detected by the kernel.
>
> From my understanding, technically it could be possible to update the
> el5 e1000e driver to support the I219-V NIC.
> However, I'm unsure if the el5 kernel offers the requisites to integrate
> the xhci_hcd module at all.
>
> How would you rate the general feasibility to integrate support for the
> NIC and the USB host controller for the el5 kernel?
>
>
> Note: with the latest kernel-lt-3.2.84-1.el5.elrepo.i686.rpm for el5
> installed, a USB keyboard can operate without the feature of toggling
> the NumLock state. When connecting or disconnecting any USB device, the
> kernel log does not show up anything and the device gets ignored.
>
> Best - Björn
>

Hi Björn,

I am in a similar situation in that I have an EL5 system and have new 
hardware arriving shortly to replace it based upon a Skylake CPU and 
B150 chipset. However, I'll be doing a fresh RHEL7 installation on this.

EL5 is dead. Well, technically not quite as End of Life is officially 
31st March next year, so it has 3 months life left. To that end, I would 
highly recommend your customer perform a fresh install of EL7 on his new 
hardware and migrate whatever he requires from his EL5 install, before 
the end of March.

Elrepo won't be undertaking any major work on EL5 now so won't be 
backporting support for that nic to EL5. I believe the reason it's not 
been updated for EL5 since Aug 2014 is that the upstream Intel source 
failed to compile against the older EL5 kernel some time back.

As I have similar hardware arriving soon, I can guarantee you I will be 
throwing all my resources at backporting anything required for EL7 on 
Skylake. I can confirm that RHEL7 already supports the Intel I219-V NIC 
8086:15b8 device:

[phil at RHEL7 ~]$ grep -i 8086 /lib/modules/*/modules.alias | grep -i 15b8
/lib/modules/3.10.0-514.2.2.el7.x86_64/modules.alias:alias 
pci:v00008086d000015B8sv*sd*bc*sc*i* e1000e
/lib/modules/3.10.0-514.el7.x86_64/modules.alias:alias 
pci:v00008086d000015B8sv*sd*bc*sc*i* e1000e


If your customer insists on sticking with EL5 then I'm afraid he's on 
his own.

As an aside, if you are able to give me a full 'lspci -nn' listing of 
the hardware, I can look in more depth as to what is natively supported 
and what still needs backporting.

Regards,

Phil