Hi Greg, On Thu, Jan 26, 2012 at 3:51 PM, Greg KH <gregkh@xxxxxxx> wrote: > On Thu, Jan 26, 2012 at 03:48:43PM -0800, Simon Glass wrote: >> Hi Greg, >> >> On Tue, Jan 24, 2012 at 9:22 AM, Greg KH <gregkh@xxxxxxx> wrote: >> > On Tue, Jan 24, 2012 at 05:57:11PM +0100, Sebastian Andrzej Siewior wrote: >> >> * Alan Stern | 2012-01-21 11:11:09 [-0500]: >> >> >> >> >Doing time-consuming things later won't make any difference. That is, >> >> >suppose the boot sequence performs activities A and B, where A takes a >> >> >long time. Doing A later, so that the boot sequence performs B and >> >> >then A, won't change the total time required. >> >> >> >> That is true. However if you show the gui _now_ and look for USB later >> >> then it feels faster and this is usually enough. >> > >> > Which has been done before, with great success (i.e. we did it for >> > Moblin boot times), so it shouldn't be that big of an issue. >> > >> > Which points out the question, exactly what is the issue here? We have >> > "multithreaded" pci driver startup for a long time now, did that stop >> > working here? If you use bootchart, does it show that the USB host >> > driver is stoping the machine from proceeding to the next stage in the >> > boot process? >> > >> > From my experience, I never saw the USB host controller get in the way >> > at all, it was always somethine else happening that caused problems >> > (i.e. video.) >> > >> > Simon, do you have boot charts anywhere showing this? >> >> I did have initcall timing when I last looked at this. USB was holding >> up progress. Sorry for the delay - I hope to get back to this next >> week. > > Are you building your USB host controllers into the kernel, or are they > modules? > > What is sitting on the USB bus that is needed for the boot process to > continue on to init and then later? Is the root disk on it? A hub with a few things on it (Ethernet, USB stick). No we don't normally have a root disk on it - we could in fact init USB *much* later and be quite happy. Sorry I don't have full answers until I get back to this. But USB does 'start' each port within the initcall which seems to take time. Maybe it is at bottom a driver issue? Regards, Simon > > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
