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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>,
	Rob Herring <rob.herring@calxeda.com>,
	Heiko Stuebner <heiko@sntech.de>,
	Dinh Nguyen <dinguyen@altera.com>,
	Jamie Iles <jamie@jamieiles.com>, Arnd Bergmann <arnd@arndb.de>
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>,
	Rob Herring <robh+dt@kernel.org>, <linux-mips@vger.kernel.org>,
	<linux-rtc@vger.kernel.org>, <devicetree@vger.kernel.org>,
	Enrico Weigelt <info@metux.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Allison Randal <allison@lohutok.net>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH v5 6/8] clocksource: dw_apb_timer_of: Fix missing clockevent timers
Date: Thu, 21 May 2020 23:48:15 +0300	[thread overview]
Message-ID: <20200521204818.25436-7-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200521204818.25436-1-Sergey.Semin@baikalelectronics.ru>

Commit 100214889973 ("clocksource: dw_apb_timer_of: use
clocksource_of_init") replaced a publicly available driver
initialization method with one called by the timer_probe() method
available after CLKSRC_OF. In current implementation it traverses
all the timers available in the system and calls their initialization
methods if corresponding devices were either in dtb or in acpi. But
if before the commit any number of available timers would be installed
as clockevent and clocksource devices, after that there would be at most
two. The rest are just ignored since default case branch doesn't do
anything. I don't see a reason of such behaviour, neither the commit
message explains it. Moreover this might be wrong if on some platforms
these timers might be used for different purpose, as virtually CPU-local
clockevent timers and as an independent broadcast timer. So in order
to keep the compatibility with the platforms where the order of the
timers detection has some meaning, lets add the secondly discovered
timer to be of clocksource/sched_clock type, while the very first and
the others would provide the clockevents service.

Fixes: 100214889973 ("clocksource: dw_apb_timer_of: use clocksource_of_init")
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
---
 drivers/clocksource/dw_apb_timer_of.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index 2db490f35c20..ab3ddebe8344 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -147,10 +147,6 @@ static int num_called;
 static int __init dw_apb_timer_init(struct device_node *timer)
 {
 	switch (num_called) {
-	case 0:
-		pr_debug("%s: found clockevent timer\n", __func__);
-		add_clockevent(timer);
-		break;
 	case 1:
 		pr_debug("%s: found clocksource timer\n", __func__);
 		add_clocksource(timer);
@@ -161,6 +157,8 @@ static int __init dw_apb_timer_init(struct device_node *timer)
 #endif
 		break;
 	default:
+		pr_debug("%s: found clockevent timer\n", __func__);
+		add_clockevent(timer);
 		break;
 	}
 
-- 
2.25.1


  parent reply	other threads:[~2020-05-21 20:49 UTC|newest]

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 ` [PATCH v5 5/8] clocksource: dw_apb_timer: Affiliate of-based timer with any CPU 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_of: Fix missing clockevent timers 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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