My Linux Conference AU slides are now posted on my server. The USB 3.0 talk went really well, and I look forward to sharing it when the LCA videos go up in the next couple weeks.
LCA was a total blast! The speakers were wonderful, and I really felt integrated into the conference and social events by the techie women of LCA. Thank you to Sara, Jo, Jacinta, Liz, and all the other Haecksen of LCA2010!
The only downside is the weather. It's really quite rainy here, although it's 10-15 degrees warmer than Portland. I think Jamey and I are going to skip the Tongariro Crossing and go straight to the glow worm caves at Te Kuiti/Waitmo. At least we'll be in a cave while it's raining!
| link | 16 comment(s)
Posted by lxr at Sun Mar 7 21:33:30 2010
Hi. Is there a documentation of XHCI for non-corporate open source developers? On Intel webpages, the documentation is hidden behind some agreement that must be signed by a corporate officer...
Posted by Sarah Sharp at Sun Mar 7 23:31:55 2010
lxr: Unfortunately, you have to sign the xHCI contributor agreement to get the xHCI specification. I don't like that setup, but that's the way it is right now. :( It might help to express the need for an open, publicly available specification by sending email to jeff.ravencraft@intel.com.
Posted by Sarah Sharp at Sun Mar 7 23:35:26 2010
x-alina: How bad of a word is it? I wasn't familiar with the word before going to the conference, and I'm not sure how the organizers picked the word Haecksen.
Posted by Paddy at Wed Mar 10 21:36:00 2010
Hi Sarah,
Do you have any idea on linux usb 3.0 gadget framework support?...
Posted by Sarah Sharp at Thu Mar 11 09:41:12 2010
Paddy: I haven't seen any effort on an open source USB 3.0 gadget driver. There was some initial interest from some companies, but I haven't seen any more emails about that.
Posted by Paddy at Fri Mar 19 00:20:15 2010
Hi Sarah,
Thanks for your replay :), Can you correct my understanding on Linux & USB 3.0?
1. I can plug USB3.0 thumb drive (which implements BOT/CBI protocol) into a Host (running Linux 2.6.31 >) having USB3.0 port. And no need to modify current in box Linux (2.6.31 >) mass storage driver stack at Host.
Only the data transfer rate (<250 MB/s) will be effected.
2. I need to implement "USB Attached SCSI" protocol (SAM4) model in MSD to get higher data rate.
Right now there is no support in Linux Host for (USB Attached SCSI Protocol) UASP devices.
My goal is to run Linux on a device (embedded with USB3.0 device controller) and to implement USB Mass Storage Device supporting "USB Attached SCSI" & "Bulk Only Transfer" protocol.
Any advice from You in this regard will be helpful to me.
Posted by x-alina at Wed Mar 24 16:00:14 2010
Haecksen is not the female version of the word hackers, the "Haecksen" are an strictly closed organization in Germany, with a binary gender thinking of the last century.
Posted by Sarah Sharp at Thu Mar 25 17:18:28 2010
x-alina: Huh. Well, I can't change the conference name now, but I'll suggest they pick a different name next year.
Posted by Sarah Sharp at Thu Mar 25 17:27:26 2010
Paddy:
Answer to 1: Yes, a USB 3.0 device with BoT will work under 2.6.31 or later kernels. I suggest you use the latest stable kernel (currently 2.6.33). You may not reach 250 MB/s with BoT; I've only seen around 160 MB/s. I haven't done any performance tuning for the xHCI driver though.
Answer to 2: Yes, you need to implement UASP on your storage device to get a transfer speed greater than 250 MB/s.
There is no UASP host-side driver yet. There is also no USB 3.0 xHCI gadget-side driver yet. The xHCI specification doesn't say how to implement the device-side controller, so there's no real standard right now. With no gadget-side hardware or specs, there hasn't been a push to make a Linux gadget-side driver for USB 3.0.
Feel free to send any more questions to the linux-USB mailing list, and CC my work address (sarah dot a dot sharp at linux dot intel dot com).
Posted by x-alina at Sun Mar 28 11:38:10 2010
P.S.: The real female version of the word hackers in German is "Hackerinnen", but this is also the big problem of this language. There are no unisex versions of this words, only a male and a female.
I really like the English language for this reason, because it has mostly only unisex versions of this words. :)
But the real post-feministic language is Klingon. ;) It has only one word for he and she. :)
Posted by paddy at Tue Mar 30 03:41:15 2010
Sarah,
Thanks for your reply, definitely I will send my query to Linux USB mailing list & actively participate in it.
Posted by Anon at Wed May 26 20:16:20 2010
Hi Sarah,
I've contacted him about open access to xHCI specs before as well, unfortunately he's not cooperative and considers your driver sufficient enough documentation.
I'm sure your driver is of great quality, but, source code is no substitute for documentation, especially when trying to create independent implementations (..as we might end up proliferating bugs).
Can you press this issue further inside Intel?
Posted by Anon at Thu Jun 10 21:31:32 2010
Any luck Sarah? don't suppose it would be possible to contact you and get a copy of them?
