[EMAIL PROTECTED] wrote: > I consequently have a bunch of questions for anyone kind enough > to answer them. > > 1. All USB host controller drivers are currently PCI > drivers. I do not know non-PCI ohci or uhci conformant > controllers are even possible. Am I correct in understanding > that these devices all use bus mastering and can access the first > 4GB of RAM, rather than using the motherboard's DMA > controller and only being able to access the first 16MB?
Just my 2c: Actually at least one non-PCI ohci exists :-) It is the embedded HC in our ST40GX1 SoC. It is a microprocessor based on a SH4 core with a number of peripherals connected to an on-chip bus called SuperHyway. The standard usb-ohci driver worked OK once I got rid of the all the PCI-ism in the code (quick hack for testing purposes only :-) I'm working now on an arch-specific PCI emulation layer that will allow devices on this bus to be seen as PCI devices and therefore leave all drivers untouched. IMVHO I still believe that there's a little bit too much PCI code in the HC drivers. With the number of embedded SoC's ever increasing there will be more host controllers that won't be PCI devices. Cheers. -- ------------------------------------------------------------ Mr. Andrea Cisternino | Tel: +44-(0)1454-462363 MCDT Division | TINA: 065 2363 STMicroelectronics Ltd. | Fax: +44-(0)1454-617910 1000 Aztec West, Almondsbury | Bristol BS32 4SQ | [EMAIL PROTECTED] United Kingdom | _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
