On Thu, 11 Jun 2009 01:45:53 +0800 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 10 Jun 2009, Alek Du wrote: > > > From b076459721690a5a03bc6490d0a98237ada74628 Mon Sep 17 00:00:00 2001 > > From: Alek Du <alek.du@xxxxxxxxx> > > Date: Wed, 10 Jun 2009 12:29:57 +0800 > > Subject: [PATCH] EHCI: Add module parameter to specify EHCI_IO_JIFFIES > > > > The default EHCI_IO_JIFFIES is just waking up system too much (~10 times per > > second) and it won't benefit those no interrupt quirk EHCI controllers. This > > patch adds an io_jiffies parameter to ehci-hcd, user either could specify the > > parameter during modprobe time or provide ehci-hcd.io_jiffies=xxxx in kernel > > cmdline for ehci-hcd built-in case. > > A better approach would be to get rid of the timer altogether except on > systems where it was really needed. Is it possible to tell at runtime > whether the controller needs the IO_WATCHDOG timer? > > Alan Stern > I guess runtime is difficult -- we need to detect if the controller miss interrupts. I think this patch is still needed, because it gives a parameter to tune the io performance for either those quirk controllers, or the good ones. Another approach is to add a item, say, need_io_watchdog to ehci-hcd structure. Those quirk controllers' driver need to fill "1" to it to explicitly say it need io watchdog. But this requires to find out which controllers in tree now need io_watchdog. Alek -- 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
