From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: - usb-improve-ehci_watchdogs-side-effect-in-cpu-power-management.patch removed from -mm tree Date: Fri, 03 Oct 2008 14:29:10 -0700 Message-ID: <200810032129.m93LTArg016669@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:60796 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753261AbYJCV3V (ORCPT ); Fri, 3 Oct 2008 17:29:21 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: yi.y.yang@intel.com, david-b@pacbell.net, greg@kroah.com, stern@rowland.harvard.edu, mm-commits@vger.kernel.org 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 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 Cc: David Brownell Cc: Alan Stern Cc: Greg KH Signed-off-by: Andrew Morton --- 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@intel.com 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