From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756414Ab0IVBtk (ORCPT ); Tue, 21 Sep 2010 21:49:40 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:62232 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755547Ab0IVBtj (ORCPT ); Tue, 21 Sep 2010 21:49:39 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=IdWYztz6MInD/LFl/HgauPlBed7fIQjRY1F/iego+bB6N9iUNrJGF0bKyL9KFsz+bq +5dHW4qpri70VZRrFTz4EBZxl9i4fmp5WXDyesjceUbkSHdRl0qB2MapPZXYssEbL1OZ Xm2mI9VJ5O4Kvf52ziQM9Vz6NJ2EhiK9Lq0ig= From: tom.leiming@gmail.com To: sameo@linux.intel.com Cc: linux-omap@vger.kernel.org, Ming Lei , Santosh Shilimkar , Balaji T K , Rajendra Nayak , Kevin Hilman , linux-kernel@vger.kernel.org Subject: [PATCH] mfd: speedup twl4030 irq response time and decrease irq disable time Date: Wed, 22 Sep 2010 09:49:31 +0800 Message-Id: <1285120171-3030-1-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 1.6.2.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ming Lei This patch sets scheduler policy of twl4030 irq thread (twl4030_irq_thread) as SCHED_FIFO to speedup irq response time, just like taken by kernel threaded irq in irq_thread (kernel/irq/manage.c). Also higher priority than that of threaded irq is taken to avoid preemption from twl4030 subchips's threaded irq handler, so pih irq disable time may be decreased. The pih irq is disabled in handle_twl4030_pih which may wakeup twl4030 irq thread, and the pih irq will be enabled again until complete of all sih irqs' handling in twl4030 irq thread. Also for each one interrupt line of twl4030 subchip, only two irq events can be buffered by twl4030(4.4.2.3 of TPS65950 TRM). Signed-off-by: Ming Lei Cc: Samuel Ortiz Cc: Santosh Shilimkar Cc: Balaji T K Cc: Rajendra Nayak Cc: Kevin Hilman Cc: linux-kernel@vger.kernel.org --- drivers/mfd/twl4030-irq.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c index 097f24d..d1e0d80 100644 --- a/drivers/mfd/twl4030-irq.c +++ b/drivers/mfd/twl4030-irq.c @@ -286,8 +286,16 @@ static int twl4030_irq_thread(void *data) long irq = (long)data; static unsigned i2c_errors; static const unsigned max_i2c_errors = 100; - - + struct sched_param param = { + .sched_priority = MAX_USER_RT_PRIO/2 + 10, + }; + + /* Take higher priority than threaded irq to make us immune of + * preemption from twl4030 subchips's threaded irq handler, then + * we can complete all SIH irqs' handling and enable PIH irq + * again asap. + * */ + sched_setscheduler(current, SCHED_FIFO, ¶m); current->flags |= PF_NOFREEZE; while (!kthread_should_stop()) { -- 1.6.2.5