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From: Afzal Mohammed <afzal@ti.com>
To: <linux-omap@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<devicetree-discuss@lists.ozlabs.org>,
	<linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>,
	Tony Lindgren <tony@atomide.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Nicolas Pitre <nico@linaro.org>,
	Santosh Shilimkar <santosh.shilimkar@ti.com>,
	Will Deacon <will.deacon@arm.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Rob Herring <rob.herring@calxeda.com>,
	Grant Likely <grant.likely@secretlab.ca>,
	Rob Landley <rob@landley.net>, Sekhar Nori <nsekhar@ti.com>,
	Syed Mohammed Khasim <khasim@ti.com>
Subject: [RFC 2/8] ARM: twd: register clock event for 1 core SMP
Date: Mon, 18 Feb 2013 12:00:15 +0530	[thread overview]
Message-ID: <a7f62b8580aa4b33d5658f4f03371a453adaea9b.1361166003.git.afzal@ti.com> (raw)
In-Reply-To: <cover.1361166003.git.afzal@ti.com>

Register percpu local timer for scheduler tick in the case of one core
SMP configuration. In other cases - secondary cpu's as well as boot
cpu's having more than one core, this is being registered as per
existing boot flow, with a difference that they happens after delay
calibration. Registering the clock for tick in case of one core should
be done before Kernel calibrates delay (this is required to boot,
unless local timer is the only one registered for tick). Registering
twd local timer at init_time (which platforms are doing now) helps
achieve that with the proposed change.

This helps in an almost booting Kernel (minimal) by only relying on
ARM parts for an A9 one core SMP.

Signed-off-by: Afzal Mohammed <afzal@ti.com>
---
 arch/arm/kernel/smp_twd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 616268c..118f4f2 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -335,6 +335,9 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 
 	twd_get_clock(np);
 
+	if (num_possible_cpus() == 1)
+		twd_timer_setup(evt);
+
 	return 0;
 
 out_irq:
-- 
1.7.12


WARNING: multiple messages have this Message-ID (diff)
From: Afzal Mohammed <afzal-l0cyMroinI0@public.gmane.org>
To: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
	linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
	Nicolas Pitre <nico-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	Sekhar Nori <nsekhar-l0cyMroinI0@public.gmane.org>,
	Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>,
	Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>,
	Santosh Shilimkar
	<santosh.shilimkar-l0cyMroinI0@public.gmane.org>,
	Syed Mohammed Khasim <khasim-l0cyMroinI0@public.gmane.org>
Subject: [RFC 2/8] ARM: twd: register clock event for 1 core SMP
Date: Mon, 18 Feb 2013 12:00:15 +0530	[thread overview]
Message-ID: <a7f62b8580aa4b33d5658f4f03371a453adaea9b.1361166003.git.afzal@ti.com> (raw)
In-Reply-To: <cover.1361166003.git.afzal-l0cyMroinI0@public.gmane.org>

Register percpu local timer for scheduler tick in the case of one core
SMP configuration. In other cases - secondary cpu's as well as boot
cpu's having more than one core, this is being registered as per
existing boot flow, with a difference that they happens after delay
calibration. Registering the clock for tick in case of one core should
be done before Kernel calibrates delay (this is required to boot,
unless local timer is the only one registered for tick). Registering
twd local timer at init_time (which platforms are doing now) helps
achieve that with the proposed change.

This helps in an almost booting Kernel (minimal) by only relying on
ARM parts for an A9 one core SMP.

Signed-off-by: Afzal Mohammed <afzal-l0cyMroinI0@public.gmane.org>
---
 arch/arm/kernel/smp_twd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 616268c..118f4f2 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -335,6 +335,9 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 
 	twd_get_clock(np);
 
+	if (num_possible_cpus() == 1)
+		twd_timer_setup(evt);
+
 	return 0;
 
 out_irq:
-- 
1.7.12

  parent reply	other threads:[~2013-02-18  6:32 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-18  6:28 [RFC 0/8] ARM: AM43 (OMAP2+) boot support Afzal Mohammed
2013-02-18  6:28 ` Afzal Mohammed
2013-02-18  6:28 ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 1/8] ARM: localtimer: return percpu clkevt on register Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` Afzal Mohammed [this message]
2013-02-18  6:30   ` [RFC 2/8] ARM: twd: register clock event for 1 core SMP Afzal Mohammed
2013-02-18 13:47   ` Rob Herring
2013-02-18 13:47     ` Rob Herring
2013-02-18 13:47     ` Rob Herring
2013-02-19  8:00     ` Mohammed, Afzal
2013-02-19  8:00       ` Mohammed, Afzal
2013-02-19  8:00       ` Mohammed, Afzal
2013-02-18  6:30 ` [RFC 3/8] ARM: twd: clock rate from DT (if no DT clk tree) Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 4/8] ARM: am33xx: ll debug config help Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 5/8] ARM: OMAP2+: am43: Kconfig Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 6/8] ARM: OMAP2+: am43: basic dt support Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 7/8] ARM: dts: am4372: initial support Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed
2013-02-18  6:30 ` [RFC 8/8] ARM: dts: am43-pre-silicon support Afzal Mohammed
2013-02-18  6:30   ` Afzal Mohammed

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