Christer Weinigel píše v Út 29. 05. 2012 v 11:07 +0200: > Hi list, > > the EHCI driver in GRUB has some known problems with low-speed transfers > and split transactions [1]. On older machines this is not a big problem > since it's possible to connect low speed devices such a USB keyboard > directly to a port and use the UHCI driver instead. But modern Intel > chipsets do not have a UHCI companion controller any more, they only > have a EHCI controller with a normal USB 2.0 rate matching hub > permanently connected to the EHCI port inside the chipset. > > Has anybody had time to look any more at the EHCI driver? Any ideas for > how to fix this?
Uff, it is little bit difficult. The reason of the problem is still not known, so it is not possible to think about solution. I am afraid nobody has time to investigate this problem, including me, unfortunately... - GRUB developers have lot of work on currently more important things and I am still too busy (and there is no chance to get more free time for me in near future). In fact there could be probably only two reasons of the problem: - my mistake in split transfer configuration (I checked it but who knows...) - GRUB "simulation" of interrupt transfer via bulk transfers is not working when it is used via EHCI split transfers From my point of view it is little bit more probable the second reason. In this case the solution could be real implementation of interrupt transfers in GRUB - at least for EHCI. It may be possible even though GRUB is not supporting CPU interrupts but currently I have no idea/time to think about. If the reason is only my mistake in EHCI code then the solution is very simple - find the bug and correct it... :-) If You have time and related knowledges or You know somebody like that, You are welcome to help us - at least to find the reason of the problem or check the EHCI split transfer code or invent implemention of interrupt transfers in EHCI GRUB driver etc... BR, Ales > > /Christer > > [1] http://lists.gnu.org/archive/html/grub-devel/2011-10/msg00007.html > > _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
