From: Rohit Vaswani <rvaswani@codeaurora.org>
To: Marc Zyngier <marc.zyngier@arm.com>,
David Brown <davidb@codeaurora.org>,
Bryan Huntsman <bryanh@codeaurora.org>,
Daniel Walker <dwalker@fifo99.com>,
Russell King <linux@arm.linux.org.uk>
Cc: Rohit Vaswani <rvaswani@codeaurora.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 RESEND 1/2] ARM: arch timer: Set the TVAL before timer is enabled
Date: Sat, 15 Sep 2012 00:41:53 -0700 [thread overview]
Message-ID: <1347694914-1457-1-git-send-email-rvaswani@codeaurora.org> (raw)
On some hardware, the timer deasserts the interrupt when a
new TVAL is written only when the enable bit is cleared.
Hence explicitly disable the timer and then program the
TVAL followed by enabling the timer.
If this order is not followed, there are chances that
you would not receive any timer interrupts.
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
---
arch/arm/kernel/arch_timer.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c04c2a6..8672a75 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -206,9 +206,10 @@ static inline void set_next_event(const int access, unsigned long evt)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
- ctrl |= ARCH_TIMER_CTRL_ENABLE;
- ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
+ ctrl &= ~(ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_MASK);
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
+ ctrl |= ARCH_TIMER_CTRL_ENABLE;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
}
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
next reply other threads:[~2012-09-15 7:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-15 7:41 Rohit Vaswani [this message]
2012-09-15 7:41 ` [PATCH v2 RESEND 2/2] ARM: local timers: add timer support using IO mapped register Rohit Vaswani
2012-09-25 19:08 ` Rohit Vaswani
2012-09-27 15:46 ` Marc Zyngier
2012-09-28 12:28 ` Mark Rutland
2012-09-28 15:57 ` Dave Martin
2012-09-28 17:15 ` Lorenzo Pieralisi
2012-10-02 11:27 ` Dave Martin
2012-10-02 13:44 ` Lorenzo Pieralisi
2012-10-02 15:03 ` Dave Martin
2012-09-15 17:00 ` [PATCH v2 RESEND 1/2] ARM: arch timer: Set the TVAL before timer is enabled David Brown
2012-09-15 19:53 ` Rohit Vaswani
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