On Tue, 6 May 2008, David Miller wrote: > > > > > > Call Trace: > > > > > > [000000000058bda8] __handle_sysrq+0xd0/0x1a0 > > > > > > [0000000000592500] sunsu_serial_interrupt+0x4e8/0x6c0 > > > > > > [000000000047dd4c] handle_IRQ_event+0x34/0xa0 > > > > > > [000000000047f2dc] handle_fasteoi_irq+0x64/0xe0 > > > > > > [000000000042d548] handler_irq+0x70/0xa0 > > > > > > [00000000004208b4] tl0_irq5+0x1c/0x20 > > > > > > [0000000000404980] __handle_softirq+0x8/0x10 > > > > > > [000000000045d9e0] run_timer_softirq+0x188/0x200 > > > > > > [00000000004590e4] __do_softirq+0x6c/0xe0 > > > > > > [00000000004591b8] do_softirq+0x60/0x80 > > > > > > [0000000000459344] irq_exit+0x6c/0xa0 > > > > > > [000000000042d558] handler_irq+0x80/0xa0 > > > > > > [00000000004208b4] tl0_irq5+0x1c/0x20 > > > > > > [fffff8006e147619] 0xfffff8006e147621 > > > > > > [000000001001d638] usb_hcd_poll_rh_status+0x40/0x180 [usbcore] > > > > > > [000000001001dafc] usb_add_hcd+0x384/0x5c0 [usbcore] > > Then my guess is that something strange is happening inside > > sunsu_serial_interrupt() or __handle_sysrq(). > > That's not how I read the trace. > > What I see is that the cpu is stuck in usb_hcd_poll_rh_status(), and > can't make any progress. > > Even if there might be some problem with sunsu_serial_interrupt() or > __handle_sysrq(), why isn't anyone willing to look at the USB portion > at the top of the backtrace at all? I'm finding that bit frustrating. Well, _I'm_ willing to look. However without an assembly listing of usb_hcd_poll_rh_status() from Meelis's system I can't tell exactly where it might be getting stuck. The two most likely possiblities are the call to hcd->driver->hub_status_data() and the spin_lock_irqsave() statement. (But I don't see how the CPU could get stuck on the spin_lock_irqsave unless it's an SMP system.) Meelis, can you provide an assembly listing of that routine? It's in drivers/usb/core/hcd.c. Alternatively, you could try adding printk messages before and after each of those statements, and see how far they get. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
