Slow boot due to USB errors

[Hans Petter Selasky]

On 05/11/14 19:07, Alan Stern wrote:
> On Sun, 11 May 2014, drago01 wrote:
>
>>>>> I know that 1-4 is the touchscreen (its an ultrabook with a
>>>>> touchscreen) ... the touchscreen itself works just fine though.
>>>>> So if it takes more time / attempts to enumerate it and it works
>>>>> eventually anyway why do we block boot on it?
>>>>
>>>> That is a question for the systemd people / list.
>>>
>>> systemd-devel@, WTF!? :)
>>> systemd ain't kernel!
>
> As I understand it (and my understanding could easily be wrong), device
> probing happens asynchronously during boot-up.  Then when the kernel is
> about to mount the real root fs, it waits for all those async probes to
> finish so that the real root device will have been found and is ready
> for use.  Thus, a device that introduces a long delay during probing
> can block booting, even if it doesn't contain the root filesystem.
>
> It's a heavy-handed approach.  Maybe it would be possible to cut the
> wait short when the root device has been found, maybe not.  I'm not an
> expert on this.
>
> Part of the problem is that the USB stack contains too many nested
> retry loops with long delays in the device initialization pathway.
> It's not clear which of them should be removed, however.

Hi,

echo "hw.usb.no_boot_wait=0" >> /boot/loader.conf

--HPS