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budrecki
05-07-2008, 09:02 PM
I've got a Tivo HD with integrated 100Mb NIC, but I've want to use my Gb USB2 NIC and when I plug it in my box comes crashing down (unalinged kernel). I'm using the custom 8.1 Gen06 kernel posted elsewhere on these forums and I'm running with 9.3 software.

Do I need to disable the integrated NIC before I attach my USB NIC ?
Do I need to 'ln -s' to my bcmenet.o native driver in /platform/lib/modules ?

jkozee
05-07-2008, 10:11 PM
You should probably stick with a neutered stock kernel until the 9.3 src is available for a custom kernel. Jamie mentioned "TickKiller" kernel crash here (http://www.dealdatabase.com/forum/showpost.php?p=295831&postcount=3). You will need your stock kernel plus replace_initd and null-linuxrc.img.gz which can be found here (http://www.dealdatabase.com/forum/showpost.php?p=275120&postcount=1).

You do not need to disable the integrated nic to use usb ethernet and you will not need a custom bcmenet once you go back to a stock kernel.

budrecki
05-08-2008, 10:58 AM
OK ... I thought this made sense, but maybe I'm missing something.

I followed your suggestion and grabbed a stock 9.3 kernel from the original Tivo HD drive. I pulled it down to one of my linux machines and used replace_initrd to patch it. I then ftp'd over to my THD and applied to the alt partition, flipped the bootpage and bounced.

Same problem still ... when I plug in my USB NIC (Airlink101), the Tivo crashes and I get the kernel alignment error on the console.

Did I miss something ?

jkozee
05-08-2008, 12:13 PM
Check that your backport drivers installed correctly

You will need the obj files from here (http://www.dealdatabase.com/forum/showpost.php?p=289690&postcount=75). For the AGIGAUSB you will need to add the ax88178 products from usb.map.additions to the usbnet section in you usb.map file. You will also need to make sure that you are using usbcore.o, usb-ohci.o, and ehci-dummy.o (renamed to ehci-hcd.o) from the obj/hosts/2.4.20_Gen06 directory. You also need to use the usbnet.o file from the obj/drivers/2.4.20-8 directory.

Jamie
05-08-2008, 02:06 PM
Just to fill in, I think the 8.x kernels are fine with 9.3. I did get a "TickKiller" crash early on on my TiVoHD, but I don't think it was due to the kernel. The applications trigger the TickKiller crash by sending an ioctl to /dev/gen-ioctl, and it looks to me like it was an application that triggered the crash, not the kernel. I've since built and used 9.2 kernels, but I don't think they behave any differently. I'll post them, eventually.

The sort of crash described here sounds like it is due to modules that are not compatible with the kernel you are using. In particular, make sure your backport usbnet.o is from the 2.4.20-8 directory and you have the Gen06 flavor of the backport host modules, as jkozee mentioned.

lgkahn
05-08-2008, 08:41 PM
as a side note just because it says gb doesn't mean it really supports those speeds well.. my feeling is that a gb usb nic which converts to serial is probably not faster than the integrated 100 mb nic.. has anyone tested this?

jkozee
05-08-2008, 10:51 PM
as a side note just because it says gb doesn't mean it really supports those speeds well.. my feeling is that a gb usb nic which converts to serial is probably not faster than the integrated 100 mb nic.. has anyone tested this?

Yes, this has been tested and the AGIGAUSB shows improvements when coupled with jumbo frames. See here (http://www.dealdatabase.com/forum/showpost.php?p=289774&postcount=269), here (http://www.dealdatabase.com/forum/showpost.php?p=295831&postcount=3), and here (http://www.dealdatabase.com/forum/showthread.php?p=289553#post289553) (and the replies that follow) for some results.

Of course, faster network transfers doesn't necessarily mean faster video transfers as there are disk and cpu bottlenecks to consider. But, on an idle system and using low ovrehead transfers like mfs_ftp, improvements can be had.

Jamie
05-09-2008, 11:02 AM
as a side note just because it says gb doesn't mean it really supports those speeds well.. my feeling is that a gb usb nic which converts to serial is probably not faster than the integrated 100 mb nic.. has anyone tested this?Gige by itself doesn't help. The TiVo is cpu limited, and all the gain comes from the lower cpu overhead you get if you use jumbo frames.

lgkahn
05-09-2008, 11:40 AM
ok so what kernel and drivers should I use for a new series 3 9.3 box to get improved performance thanks

Jamie
05-09-2008, 12:29 PM
ok so what kernel and drivers should I use for a new series 3 9.3 box to get improved performance thanksYou need jumbo frame capable switches and NIC's and you might need to partition off a jumbo frame only subnet/vlan, if you can't make everything on your network jumbo frame capable. If you are willing to do that, the standard backport (http://www.dealdatabase.com/forum/showthread.php?t=44114) usbnet can support jumbo frames on ax88178 devices. You can use the stock kernel, but for best performance, use a custom kernel (http://www.dealdatabase.com/forum/showthread.php?t=54047) with netfilter turned off. That helps even without jumbo frames.

lrhorer
10-25-2009, 07:40 PM
What, exactly, does netfilter do?

jt1134
10-25-2009, 09:28 PM
http://lmgtfy.com/?q=netfilter

lrhorer
11-01-2009, 01:26 AM
Oh! I hadn't thought of it s being a part of the standard Linux kernel. For some reason I had it in my mind it was part of the custom TiVo kernel, so I didn't expect it to be generally available on the web. Silly me.