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From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Thomas Gleixner <tglx@linutronix.de>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
	Serge Semin <fancer.lancer@gmail.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Paul Burton <paulburton@kernel.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh+dt@kernel.org>,
	<linux-mips@vger.kernel.org>, <linux-rtc@vger.kernel.org>,
	<devicetree@vger.kernel.org>,
	Allison Randal <allison@lohutok.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Alexios Zavras <alexios.zavras@intel.com>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH v5 5/8] clocksource: dw_apb_timer: Affiliate of-based timer with any CPU
Date: Thu, 21 May 2020 23:48:14 +0300
Message-ID: <20200521204818.25436-6-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200521204818.25436-1-Sergey.Semin@baikalelectronics.ru>

Currently any DW APB Timer device detected in OF is bound to CPU #0.
Doing so is redundant since DW APB Timer isn't CPU-local timer, but as
having APB interface is normally accessible from any CPU in the system. By
artificially affiliating the DW timer to the very first CPU we may and in
our case will make the clockevent subsystem to decline the more performant
real CPU-local timers selection in favor of in fact non-local and
accessible over a slow bus - DW APB Timers.

Let's not affiliate the of-detected DW APB Timers to any CPU. By doing so
the clockevent framework would prefer to select the real CPU-local timer
instead of DW APB one. Otherwise if there is no other than DW APB device
for clockevents tracking then it will be selected.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: devicetree@vger.kernel.org

---

Changelog v5:
- This is a new patch created after reconsidering the solution of the DW
  APB Timer CPU-affiliation problem.
---
 drivers/clocksource/dw_apb_timer_of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index 8c28b127759f..2db490f35c20 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -73,7 +73,7 @@ static void __init add_clockevent(struct device_node *event_timer)
 
 	timer_get_base_and_rate(event_timer, &iobase, &rate);
 
-	ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
+	ced = dw_apb_clockevent_init(-1, event_timer->name, 300, iobase, irq,
 				     rate);
 	if (!ced)
 		panic("Unable to initialise clockevent device");
-- 
2.25.1


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 20:48 [PATCH v5 0/8] clocksource: Fix MIPS GIC and DW APB Timer for Baikal-T1 SoC support Serge Semin
2020-05-21 20:48 ` [PATCH v5 1/8] dt-bindings: rtc: Convert snps,dw-apb-timer to DT schema Serge Semin
2020-05-21 20:48 ` [PATCH v5 2/8] dt-bindings: timer: Move snps,dw-apb-timer DT schema from rtc Serge Semin
2020-05-21 20:48 ` [PATCH v5 3/8] dt-bindings: interrupt-controller: Convert mti,gic to DT schema Serge Semin
2020-05-21 20:48 ` [PATCH v5 4/8] clocksource: dw_apb_timer: Make CPU-affiliation being optional Serge Semin
2020-06-01 13:11   ` [tip: timers/core] " tip-bot2 for Serge Semin
2020-05-21 20:48 ` Serge Semin [this message]
2020-06-01 13:11   ` [tip: timers/core] clocksource: dw_apb_timer: Affiliate of-based timer with any CPU tip-bot2 for Serge Semin
2020-05-21 20:48 ` [PATCH v5 6/8] clocksource: dw_apb_timer_of: Fix missing clockevent timers Serge Semin
2020-06-01 13:11   ` [tip: timers/core] " tip-bot2 for Serge Semin
2020-05-21 20:48 ` [PATCH v5 7/8] clocksource: mips-gic-timer: Register as sched_clock Serge Semin
2020-06-01 13:11   ` [tip: timers/core] " tip-bot2 for Paul Burton
2020-05-21 20:48 ` [PATCH v5 8/8] clocksource: mips-gic-timer: Mark GIC timer as unstable if ref clock changes Serge Semin
2020-06-01 13:11   ` [tip: timers/core] " tip-bot2 for Serge Semin
2020-05-22 15:28 ` [PATCH v5 0/8] clocksource: Fix MIPS GIC and DW APB Timer for Baikal-T1 SoC support Daniel Lezcano
2020-05-22 15:41   ` Serge Semin
2020-05-22 15:44     ` Daniel Lezcano
2020-05-22 16:02       ` Serge Semin

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