Messages in this thread | | | Date | Tue, 06 Apr 2004 14:32:19 +0930 | From | Malcolm Blaney <> | Subject | Re: mark_offset_tsc() hangs usb |
| |
I wrote:
> I have been trying to fix a problem related to usb, with the help of the > usb-dev list. Plugging in a usb device hangs my computer when bandwidth > reclamation (fsbr) is turned on in the uhci-hcd driver. > > I have found though, that when an interrupt is triggered by plugging in > a usb device, the timer_interrupt() function in arch/i386/kernel/time.c > is reached, and the computer hangs in mark_offset_tsc() in > timers/timer_tsc.c. I removed the call to this function in > timer_interrupt() and then usb worked as normal. I'm hoping there's a > better way to get usb working than this though! This doesn't happen when > fsbr is switched off. > > The computer has a Crusoe TM5400 cpu and a VIA VT82C686A controller.
I've been trying to work out what goes wrong in mark_offset_tsc() and found that it's just the outb_p() & inb_p() calls that are causing the problem. I found a thread relating to this, http://www.ussg.iu.edu/hypermail/linux/kernel/0309.2/1039.html, and tried the line: #define __SLOW_DOWN_IO__ "" which also allowed usb to work normally. Since this is just avoiding the read or write to port 0x80, is this a sign of having dodgy hardware? The thread doesn't talk about writing to the port as being fatal, even if it does cause problems for some people.
Anybody got a better fix?
Malcolm.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |