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From: Dongsheng Wang <dongsheng.wang@freescale.com>
To: <scottwood@freescale.com>
Cc: linuxppc-dev@lists.ozlabs.org,
	Wang Dongsheng <dongsheng.wang@freescale.com>
Subject: [PATCH v2 1/2] powerpc/mpic_timer: fix the time is not accurate caused by GTCRR toggle bit
Date: Mon, 6 Jan 2014 13:23:30 +0800	[thread overview]
Message-ID: <1388985811-32495-1-git-send-email-dongsheng.wang@freescale.com> (raw)

From: Wang Dongsheng <dongsheng.wang@freescale.com>

When the timer GTCCR toggle bit is inverted, we calculated the rest
of the time is not accurate. So we need to ignore this bit.

Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com>
---
v2:
No change.

diff --git a/arch/powerpc/sysdev/mpic_timer.c b/arch/powerpc/sysdev/mpic_timer.c
index 22d7d57..70dcf9c 100644
--- a/arch/powerpc/sysdev/mpic_timer.c
+++ b/arch/powerpc/sysdev/mpic_timer.c
@@ -41,6 +41,7 @@
 #define MPIC_TIMER_TCR_ROVR_OFFSET	24
 
 #define TIMER_STOP			0x80000000
+#define GTCCR_TOG			0x80000000
 #define TIMERS_PER_GROUP		4
 #define MAX_TICKS			(~0U >> 1)
 #define MAX_TICKS_CASCADE		(~0U)
@@ -327,11 +328,13 @@ void mpic_get_remain_time(struct mpic_timer *handle, struct timeval *time)
 	casc_priv = priv->timer[handle->num].cascade_handle;
 	if (casc_priv) {
 		tmp_ticks = in_be32(&priv->regs[handle->num].gtccr);
+		tmp_ticks &= ~GTCCR_TOG;
 		ticks = ((u64)tmp_ticks & UINT_MAX) * (u64)MAX_TICKS_CASCADE;
 		tmp_ticks = in_be32(&priv->regs[handle->num - 1].gtccr);
 		ticks += tmp_ticks;
 	} else {
 		ticks = in_be32(&priv->regs[handle->num].gtccr);
+		ticks &= ~GTCCR_TOG;
 	}
 
 	convert_ticks_to_time(priv, ticks, time);
-- 
1.8.5

             reply	other threads:[~2014-01-06  5:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-06  5:23 Dongsheng Wang [this message]
2014-01-06  5:23 ` [PATCH v2 2/2] powerpc/mpic_timer: fix convert ticks to time subtraction overflow Dongsheng Wang

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