Re: Re: Reliable unreliability with D-Link DWL-122 USB

--- [email protected] wrote:
> From your summary of events, it looks to me as if you
> have something in your bootup scripts that is
> loading the prism2_usb module manually and
> then bringing up the hardware (i.e. firmware upload,
> autojoin etc etc), and that this is happening ahead
> of the hotplug (or more likely coldplug of the pci bus)
> events.

I'm not aware of having set this up, and grep doesn't reveal any
references to prism2 or wlan in /etc/init.d (except for the default
wlan script, which isn't symlinked in any of the rc.x directories). I
still have no execute permissions on /etc/hotplug/usb.rc .

There is some non-usb-related hotplug activity before the first mention
of prism2_usb in the log: module/driver adds for i2c stuff. In my
overzealous abridging of the log as I was trying to make sense of it, I
missed out some of the early stages. Here's more detail of the start.

  [ syslogd restart, klogd, RAM, PCI resources, CPU, lm_sensors,
    SELinux, PCI, ACPI, pnp ]
pnp: PnP ACPI: found 12 devices
kernel: usbcore: registered new driver usbfs
kernel: usbcore: registered new driver hub
  [ Then various pci, pnp, apm stuff ]
kernel: pci_hotplug: PCI Hot Plug PCI Core version: 0.5
  [ Then acpi, isapnp, agpgart, ide... ]
kernel: usbcore: registered new driver hiddev
usbcore: registered new driver usbhid
  [ Then hci, md ]
kernel: NET: Registered protocol family 2 [then 1, 17]
  [ Then IP, TCP, IPsec ]
kernel: ACPI wakeup devices:
kernel: SLPB PCI0 USB0 USB1 USB2 USB6 USB7 USB8 USB9 LAN0 UAR1 ECP1
  [ Then device-mapper, kjournald ]
  [ Next come lots of i2c-related hotplug add events, e.g. ...]
default.hotplug[4122]: arguments (module) env (SUBSYSTEM=module
OLDPWD=/ DEVPATH=/module/i2c_isa PATH=/bin:/sbin:/usr/sbin:/usr/bin
ACTION=add PWD=/etc/hotplug HOME=/ SHLVL=2 DEBUG=yes SEQNUM=608
_=/bin/env)
  [ Then floppy, then eth0 driver (onboard) ]
kernel: prism2usb_init: prism2_usb.o: 0.2.1-pre26 Loaded
kernel: prism2usb_init: dev_info is: prism2_usb
usbcore: registered new driver prism2_usb
  [ Then ACPI/PCI IRQ stuff ]
kernel: ehci_hcd 0000:00:10.3: EHCI Host Controller [& bus, hub]
kernel: USB Universal Host Controller Interface driver v2.2 [& bus,
hub]
kernel: usb 2-1: new full speed USB device using uhci_hcd and address 2
  [ Then firmware upload, linkstatus=CONNECTED. ]

I'm still not sure quite how the prism2_usb initialisation is
triggered, but it happens amidst lots of other hardware initialisation
and immediately after eth0. Neither eth0 nor wlan0 is set to start on
boot in /etc/sysconfig .

> My guess is that the hotplug event
> with DEVPATH=/devices/pci0000:00/0000:00:10.0/usb2/2-0:1.0
> looks up (from /sys/$DEVPATH) vendorString and other
> attributes in the usb.agent script. The fact that
> this lookup is happening AFTER your prism card is already
> with 'linkstatus=CONNECTED' could be your downfall!

Yes, that seems likely.

> [What I don't understand is how you get two 'net.agent'
> related hotplug events. In my understanding you should only
> ever get one of these when the prism2_usb driver first
> 'claims' the prism card - but I don't think its that important to
> this discussion.]

On closer inspection I actually get three: one each for eth0, wlan0,
sit0.

> In my system, I have nothing in my boot scripts to try and bring up
> the card - I rely purely on hotplug.

I _thought_ that's what I was doing! :-)

> Overall, the easiest workaround, is to put a sleep in somewhere to
> delay the card being setup.

Yes, I've always thought a long sleep is the best solution!

Thanks again,

Dave


		
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