The patch titled usb: improve ehci_watchdog's side effect in CPU power management has been removed from the -mm tree. Its filename was usb-improve-ehci_watchdogs-side-effect-in-cpu-power-management.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: usb: improve ehci_watchdog's side effect in CPU power management From: Yi Yang <yi.y.yang@xxxxxxxxx> ehci_watchdog will wake up CPU very frequently so that CPU stays at C3 very short, average residence time is about 50 ms on Aspire One, but we expect it should be about 1 second or more, so this kind of periodic timer is very bad for power saving. We can't remove this timer because of some bad USB controller chipset, but at least we should reduce its side effect to as low as possible. This patch can make CPU stay at C3 longer, average residence time is about twice as long as original. Signed-off-by: Yi Yang <yi.y.yang@xxxxxxxxx> Cc: David Brownell <david-b@xxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Greg KH <greg@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/usb/host/ehci.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff -puN drivers/usb/host/ehci.h~usb-improve-ehci_watchdogs-side-effect-in-cpu-power-management drivers/usb/host/ehci.h --- a/drivers/usb/host/ehci.h~usb-improve-ehci_watchdogs-side-effect-in-cpu-power-management +++ a/drivers/usb/host/ehci.h @@ -181,14 +181,16 @@ timer_action (struct ehci_hcd *ehci, enu * the async ring; just the I/O watchdog. Note that if a * SHRINK were pending, OFF would never be requested. */ - if (timer_pending(&ehci->watchdog) - && ((BIT(TIMER_ASYNC_SHRINK) | BIT(TIMER_ASYNC_OFF)) - & ehci->actions)) - return; + enum ehci_timer_action oldactions = ehci->actions; if (!test_and_set_bit (action, &ehci->actions)) { unsigned long t; + if (timer_pending(&ehci->watchdog) + && ((BIT(TIMER_ASYNC_SHRINK) | BIT(TIMER_ASYNC_OFF)) + & oldactions)) + return; + switch (action) { case TIMER_IO_WATCHDOG: t = EHCI_IO_JIFFIES; @@ -204,7 +206,7 @@ timer_action (struct ehci_hcd *ehci, enu t = DIV_ROUND_UP(EHCI_SHRINK_FRAMES * HZ, 1000) + 1; break; } - mod_timer(&ehci->watchdog, t + jiffies); + mod_timer(&ehci->watchdog, round_jiffies(t + jiffies)); } } _ Patches currently in -mm which might be from yi.y.yang@xxxxxxxxx are git-acpi.patch lib-pull-base-guessing-logic-to-helper-function.patch lib-trivial-whitespace-tidy.patch lib-remove-defining-macros-for-strict_strto.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html