[PATCH RT 06/15] ARM: imx: always use TWD on IMX6Q

From: Steven Rostedt
Date: Tue Jul 12 2016 - 10:30:06 EST


3.18.36-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

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 <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
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 11b2957f792b..41792b506b2e 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -605,7 +605,7 @@ 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