Bug #2244
Updated by liweitianux almost 5 years ago
Versions: Workstation: Lenovo Thinkcentre M58p DragonFlyBSD: v2.13.0.357.gcdb8af-DEVELOPMENT X86_64_GENERIC x86_64 ################ Problem Description: My system hangs during boot if a USB mass storage device/stick is connected. By hang I mean no more output is shown and I cannot turn off/on num lock key on keyboard. A hard reset is needed at this stage. This prevents me from installing DragonFlyBSD from a USB stick. I first noticed the problem when trying to boot via USB using the 2011 Nov 17th "DragonFly-x86_64-LATEST-IMG.img". I haven't tried older versions. I can connect and use the USB mass storage device/stick after boot without problem, and shutdown while attached without problem. ################ I recompiled kernel with "options USB_DEBUG" and booted with verbose logging option. The last lines shown are: uhci1: <UHCI (generic) USB controller> [tentative] port 0x1860-0x187f irq 17 at device 26.1 on pci0 uhci1: Reserved 0x20 bytes for rid 0x20 type 4 at 0x1860 uhci1: LegSup = 0x0010 ################ From pciconf -lv: uhci0@pci0:0:26:0: class=0x0c0300 card=0x304817aa chip=0x3a678086 rev=0x02 hdr=0x00 vendor = 'Intel Corporation' device = 'USB UHCI Controller' class = serial bus subclass = USB uhci1@pci0:0:26:1: class=0x0c0300 card=0x304817aa chip=0x3a688086 rev=0x02 hdr=0x00 vendor = 'Intel Corporation' device = 'USB UHCI Controller' class = serial bus subclass = USB ################ I put kprintf's in various kernel source files to find where it hangs. (Please note that I do not know anything about the kernel and very little about C). This is what I found: Function "uhci_pci_attach(device_t self)" is called from /usr/src/sys/bus/usb/uhci_pci.c uhci_pci_attach() calls "err = uhci_init(sc);" which is in /usr/src/sys/bus/usb/uhci.c uhci_init() calls "uhci_globalreset(sc);" which is in /usr/src/sys/bus/usb/uhci.c uhci_globalreset() calls "usb_delay_ms(&sc->sc_bus, USB_BUS_RESET_DELAY);" which is in /usr/src/sys/bus/usb/usb_subr.c usb_delay_ms calls "delay((ms+1) * 1000);" with value 101000 (ms is 100). ... ... It appears that "delay((ms+1) * 1000);" never returns. I think this because I have a kprintf() after the delay(). delay() is defined as DELAY in /usr/src/sys/bus/usb/usb_subr.c. DELAY is defined in sys/systm.h but I cannot find the source file containing the DELAY function. ################ /usr/src/sys/bus/usb/usb_subr.c with the extra kprintfs: /* Delay for a certain number of ms */ void usb_delay_ms(usbd_bus_handle bus, u_int ms) { kprintf("AK: at start of function usb_delay_ms\n"); /* Wait at least two clock ticks so we know the time has passed. */ if (bus->use_polling || cold) { kprintf("AK: usb_delay_ms: in if cold and calling delay.\nAK: Value of ms after math: %d\n", (ms+1)*1000); delay((ms+1) * 1000); kprintf("AK: usb_delay_ms: finished delay\n"); } else { kprintf("AK: usb_delay_ms: in else about about to do tsleep\n"); tsleep(&ms, 0, "usbdly", (ms*hz+999)/1000 + 1); } kprintf("AK: at end of usb_delay_ms\n"); } ################ Attached dmesg and messages files taken after verbose boot without the usb stick attached.