From: <ying.zhang22455@nxp.com>
To: <linux-kernel@vger.kernel.org>
Cc: <jiafei.pan@nxp.com>, Meng Yi <meng.yi@nxp.com>
Subject: [PATCH 5/5] Fix errata A-007728 for flextimer
Date: Fri, 21 Apr 2017 15:42:47 +0800 [thread overview]
Message-ID: <1492760567-27894-5-git-send-email-ying.zhang22455@nxp.com> (raw)
In-Reply-To: <1492760567-27894-1-git-send-email-ying.zhang22455@nxp.com>
From: Meng Yi <meng.yi@nxp.com>
If the FTM counter reaches the FTM_MOD value between the reading of the
TOF bit and the writing of 0 to the TOF bit, the process of clearing the
TOF bit does not work as expected when FTMx_CONF[NUMTOF] != 0 and the
current TOF count is less than FTMx_CONF[NUMTOF]. If the above condition
is met, the TOF bit remains set. If the TOF interrupt is enabled
(FTMx_SC[TOIE] = 1), the TOF interrupt also remains asserted.
Above is the errata discription
In one word: software clearing TOF bit not works when FTMx_CONF[NUMTOF]
was seted as nonzero and FTM counter reaches the FTM_MOD value.
The workaround is clearing TOF bit until it works(FTM counter doesn't
always reache the FTM_MOD anyway),which may cost some cycles.
Signed-off-by: Meng Yi <meng.yi@nxp.com>
---
drivers/clocksource/fsl_ftm_timer.c | 8 ++++----
drivers/soc/fsl/layerscape/ftm_alarm.c | 8 ++++----
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/clocksource/fsl_ftm_timer.c b/drivers/clocksource/fsl_ftm_timer.c
index 738515b..770bbbc 100644
--- a/drivers/clocksource/fsl_ftm_timer.c
+++ b/drivers/clocksource/fsl_ftm_timer.c
@@ -83,11 +83,11 @@ static inline void ftm_counter_disable(void __iomem *base)
static inline void ftm_irq_acknowledge(void __iomem *base)
{
- u32 val;
+ unsigned int timeout = 100;
- val = ftm_readl(base + FTM_SC);
- val &= ~FTM_SC_TOF;
- ftm_writel(val, base + FTM_SC);
+ while ((FTM_SC_TOF & ftm_readl(base + FTM_SC)) && timeout--)
+ ftm_writel(ftm_readl(base + FTM_SC) & (~FTM_SC_TOF),
+ base + FTM_SC);
}
static inline void ftm_irq_enable(void __iomem *base)
diff --git a/drivers/soc/fsl/layerscape/ftm_alarm.c b/drivers/soc/fsl/layerscape/ftm_alarm.c
index c42b26b..c0b8ae1 100644
--- a/drivers/soc/fsl/layerscape/ftm_alarm.c
+++ b/drivers/soc/fsl/layerscape/ftm_alarm.c
@@ -78,11 +78,11 @@ static inline void ftm_counter_disable(void __iomem *base)
static inline void ftm_irq_acknowledge(void __iomem *base)
{
- u32 val;
+ unsigned int timeout = 100;
- val = ftm_readl(base + FTM_SC);
- val &= ~FTM_SC_TOF;
- ftm_writel(val, base + FTM_SC);
+ while ((FTM_SC_TOF & ftm_readl(base + FTM_SC)) && timeout--)
+ ftm_writel(ftm_readl(base + FTM_SC) & (~FTM_SC_TOF),
+ base + FTM_SC);
}
static inline void ftm_irq_enable(void __iomem *base)
--
2.1.0.27.g96db324
prev parent reply other threads:[~2017-04-21 7:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-21 7:42 [PATCH 1/5] soc: fsl: add support for arm64/Layerscape SOC specific drivers ying.zhang22455
2017-04-21 7:42 ` [PATCH 2/5] soc: fsl: add flextimer module alarm driver for Layerscape ying.zhang22455
2017-04-21 12:51 ` kbuild test robot
2017-04-21 17:01 ` kbuild test robot
2017-04-21 7:42 ` [PATCH 3/5] arm64: ls1021a: dts: add ftm0 nodes ying.zhang22455
2017-04-21 7:42 ` [PATCH 4/5] arm64: ls1043a: dts: add rcpm and " ying.zhang22455
2017-04-21 7:42 ` ying.zhang22455 [this message]
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