From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH RT 11/20] ARM: imx: always use TWD on IMX6Q Date: Tue, 12 Jul 2016 10:24:16 -0400 Message-ID: <20160712142419.367116752@goodmis.org> References: <20160712142405.634544943@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker To: linux-kernel@vger.kernel.org, linux-rt-users Return-path: Content-Disposition: inline; filename=0011-ARM-imx-always-use-TWD-on-IMX6Q.patch Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org 4.1.27-rt31-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior There is no reason to limit the TWD to be used on SMP kernels only if the hardware has it available. On Wandboard i.MX6SOLO, running PREEMPT-RT and cyclictest I see as max immediately after start in idle: UP : ~90us SMP: ~50us UP + TWD: ~20us. Based on this numbers I prefer the TWD over the slightly slower MXC timer. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt --- arch/arm/mach-imx/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig index 3a3d3e9d7bfd..92c0cf1276fe 100644 --- a/arch/arm/mach-imx/Kconfig +++ b/arch/arm/mach-imx/Kconfig @@ -558,7 +558,7 @@ config SOC_IMX6Q bool "i.MX6 Quad/DualLite support" select ARM_ERRATA_764369 if SMP select HAVE_ARM_SCU if SMP - select HAVE_ARM_TWD if SMP + select HAVE_ARM_TWD select PCI_DOMAINS if PCI select PINCTRL_IMX6Q select SOC_IMX6 -- 2.8.1