Re: new mail: USB controller problem on MIPSEL embedded board
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel,gmane.linux.ports.mips |
|---|---|
| Message-ID | <[email protected]> |
On Sun, 26 Aug 2007, Paolo Giarrusso wrote: > 2007/8/25, David Brownell <[email protected]>: > > > http://forums.viaarena.com/messageview.aspx?catid=16&threadid=73502&enterthread=y > > > > Interesting, so that "performance drops after starting EHCI" > > issue shows up with MS-Windows too. Now all we need is to > > have someone throw a logic analyser on a PCI bus that's > > experiencing that problem, and maybe we can get clues... :) > > Well - is there anybody who has the experience to do that? It's not a matter of experience -- it's a matter of having the right equipment. Logic analyzers aren't cheap. > Alan had an > old VIA card (older than mine), and _maybe_ I could send one of these > DVB sticks to try reproducing the problem. > > Would it be useful to contact DVB developers so that they try > understanding which USB features they are trying to use? As I've said, > any other USB highspeed or lowspeed device works well in this board. Perhaps if you knew exactly what URB triggered the problem it might help. Maybe. > I > was CC'ing the dvb mailing list but all mails were rejected since I'm > not subscribed. There's an easy solution to that... :-) > > That page *does* suggest the VIA parts don't obey chunks of > > the PCI spec ... it's not just EHCI they have problems with. > > No idea with that - they claim that motherboard chipset does not > support "bus parking", but I'm not able to grasp what you say. > However, I had tested without success (but not in so much detail) > other DVB sticks, even from other vendors and even USB 1.1 - so it is > not only EHCI broken, it is the whole controller. USB 1.1? You mean a full-speed stick has the same problem? That's definitely worth pursuing. We've never seen this sort of problem with a UHCI controller. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel