[PATCH] ARM: omap2: am437x: rollback to use omap3_gptimer_timer_init()
From: grygorii.strashko@ti.com (Grygorii Strashko)
Date: 2016-04-12 10:42:55
Also in:
linux-omap
Subsystem:
arm port, omap2+ support, the rest · Maintainers:
Russell King, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
The commit 55ee7017ee31 ("arm: omap2: board-generic: use
omap4_local_timer_init for AM437x") unintentionally changes the
clocksource devices for AM437x from OMAP GP Timer to SyncTimer32K.
Unfortunately, the SyncTimer32K is starving from frequency deviation
as mentioned in commit 5b5c01359152 ("ARM: OMAP2+: AM43x: Use gptimer
as clocksource") and, as reported by Franklin [1], even its monotonic
nature is under question (most probably there is a HW issue, but it's
still under investigation).
Taking into account above facts It's reasonable to rollback to the use
of omap3_gptimer_timer_init().
[1] http://www.spinics.net/lists/linux-omap/msg127425.html
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Lokesh Vutla <redacted>
Reported-by: Cooper Jr., Franklin <redacted>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
arch/arm/mach-omap2/board-generic.c | 2 +-
arch/arm/mach-omap2/timer.c | 7 +++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
index bab814d..60f5e83 100644
--- a/arch/arm/mach-omap2/board-generic.c
+++ b/arch/arm/mach-omap2/board-generic.c@@ -306,7 +306,7 @@ DT_MACHINE_START(AM43_DT, "Generic AM43 (Flattened Device Tree)") .init_late = am43xx_init_late, .init_irq = omap_gic_of_init, .init_machine = omap_generic_init, - .init_time = omap4_local_timer_init, + .init_time = omap3_gptimer_timer_init, .dt_compat = am43_boards_compat, .restart = omap44xx_restart, MACHINE_END
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 6261e93..7cc055c 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c@@ -500,16 +500,19 @@ void __init omap3_secure_sync32k_timer_init(void) } #endif /* CONFIG_ARCH_OMAP3 */ -#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) +#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \ + defined(CONFIG_SOC_AM43XX) void __init omap3_gptimer_timer_init(void) { __omap_sync32k_timer_init(2, "timer_sys_ck", NULL, 1, "timer_sys_ck", "ti,timer-alwon", true); + if (of_have_populated_dt()) + clocksource_probe(); } #endif #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \ - defined(CONFIG_SOC_DRA7XX) || defined(CONFIG_SOC_AM43XX) + defined(CONFIG_SOC_DRA7XX) static void __init omap4_sync32k_timer_init(void) { __omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
--
2.8.1