lkml.org 
[lkml]   [2017]   [Apr]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5/5] Fix errata A-007728 for flextimer
Date
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
\
 
 \ /
  Last update: 2017-04-21 10:00    [W:0.076 / U:5.052 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site