From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47054 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752355AbdAMMEX (ORCPT ); Fri, 13 Jan 2017 07:04:23 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Cooper Jr., Franklin" , Grygorii Strashko , Lokesh Vutla , Keerthy , Tony Lindgren Subject: [PATCH 4.9 54/59] ARM: omap2+: am437x: rollback to use omap3_gptimer_timer_init() Date: Fri, 13 Jan 2017 13:02:01 +0100 Message-Id: <20170113113841.428238826@linuxfoundation.org> In-Reply-To: <20170113113839.364876751@linuxfoundation.org> References: <20170113113839.364876751@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Grygorii Strashko commit f86a2c875fd146d9b82c8fdd86d31084507bcf4c upstream. 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 Fixes: 55ee7017ee31 ("arm: omap2: board-generic: use omap4_local_timer_init for AM437x") Reported-by: Cooper Jr., Franklin Signed-off-by: Grygorii Strashko Signed-off-by: Lokesh Vutla Signed-off-by: Keerthy Signed-off-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman --- arch/arm/mach-omap2/board-generic.c | 2 +- arch/arm/mach-omap2/timer.c | 9 +++++---- 2 files changed, 6 insertions(+), 5 deletions(-) --- 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 .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 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -510,18 +510,19 @@ void __init omap3_secure_sync32k_timer_i } #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); - - clocksource_probe(); + 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",