http://bugzilla.kernel.org/show_bug.cgi?id=13405
--- Comment #13 from Zbigniew Luszpinski <[email protected]> 2009-07-06 20:00:44 --- Hi ykzhao, thank you for response :) The usb bug I encounter does not disappear if I use I8259 by issuing noapic. It is only very, very rare that way (it only appears immediately when using torrent or fast ftp when downloading big file or other very fast and intensive job). The APIC seems to be faster than PIC thus bug is more visible. Because slow usb devices work perfect and on Linux, IRQs are never shared, the only thing to check is latency. Fast usb devices use bulk/iso transfers which are different than keyboard/mouse or other slow usb device transfers use. For example during downloading 4,3 MB e2fsprogs-1.41.7.tar.gz using wget from fast ftp server I get constant 124kb/s. After short time of download usb hangs for a second which wget shows as drop in transfer to 23kb/s but soon transfer goes back to 124kb/s. The download continues and the situation happens again after a while and download still continues at 124kb/s. The third hang is deadly. USB is not responding till reboot. It looks to me ohci controller is so slow it is unable to keep up with system. When overloaded with data it hangs. So I modified ohci usb driver source code (ohci-q.c, ohci-hub.c) by adding mdelay(5); before most of ohci_writel(...) and ohci_readl(...). After recompilation and reboot I used ohci usb without noapic workaround for much longer time without crashing. However after this modification usb hangs immediately after hotpluging other usb device so my ugly hack did not fix all the issues. :( I will ask on mail list how to slow down ohci controller I/O RW in smart way when using bulk/iso transfers without hanging hotplug. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ------------------------------------------------------------------------------ _______________________________________________ acpi-bugzilla mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
