[PATCH v1] i2c: designware: save the preset value of DW_IC_SDA_HOLD
There are several ways to set the SDA hold time for i2c controller,
including: Device Tree, built-in device properties and ACPI. However,
if the SDA hold time is not specified by above method, we should
read the value, where it is preset by firmware, and save it to
sda_hold_time. This is needed because when i2c controller enters
runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
default value. And during runtime resume, i2c_dw_init will be called
to reconfigure i2c controller. If sda_hold_time is zero, the chipset
default hold time will be used, that will be too short for some
platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
value should be kept by sda_hold_time.
Signed-off-by: Zhuo-hao Lee <zhuo-hao@intel.com>
---
drivers/i2c/busses/i2c-designware-core.c | 16 ++--
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-core.c
b/drivers/i2c/busses/i2c-designware-core.c
index c6922b8..fcd973d 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -367,13 +367,17 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Configure SDA Hold Time if required */
- if (dev->sda_hold_time) {
- reg = dw_readl(dev, DW_IC_COMP_VERSION);
- if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
+ reg = dw_readl(dev, DW_IC_COMP_VERSION);
+ if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
+ if (dev->sda_hold_time) {
dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
- else
- dev_warn(dev->dev,
- "Hardware too old to adjust SDA hold time.");
+ } else {
+ /* Keep previous hold time setting if no one set it */
+ dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+ }
+ } else {
+ dev_warn(dev->dev,
+ "Hardware too old to adjust SDA hold time.\n");
}
/* Configure Tx/Rx FIFO threshold levels */
--
1.9.1
[PATCH v1] i2c: designware: save the preset value of DW_IC_SDA_HOLD
There are several ways to set the SDA hold time for i2c controller,
including: Device Tree, built-in device properties and ACPI. However,
if the SDA hold time is not specified by above method, we should
read the value, where it is preset by firmware, and save it to
sda_hold_time. This is needed because when i2c controller enters
runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
default value. And during runtime resume, i2c_dw_init will be called
to reconfigure i2c controller. If sda_hold_time is zero, the chipset
default hold time will be used, that will be too short for some
platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
value should be kept by sda_hold_time.
Signed-off-by: Zhuo-hao Lee
---
drivers/i2c/busses/i2c-designware-core.c | 16 ++--
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-core.c
b/drivers/i2c/busses/i2c-designware-core.c
index c6922b8..fcd973d 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -367,13 +367,17 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Configure SDA Hold Time if required */
- if (dev->sda_hold_time) {
- reg = dw_readl(dev, DW_IC_COMP_VERSION);
- if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
+ reg = dw_readl(dev, DW_IC_COMP_VERSION);
+ if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
+ if (dev->sda_hold_time) {
dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
- else
- dev_warn(dev->dev,
- "Hardware too old to adjust SDA hold time.");
+ } else {
+ /* Keep previous hold time setting if no one set it */
+ dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+ }
+ } else {
+ dev_warn(dev->dev,
+ "Hardware too old to adjust SDA hold time.\n");
}
/* Configure Tx/Rx FIFO threshold levels */
--
1.9.1
[PATCH v3] alarmtimer: fix unexpected rtc interrupt when system resume from S3
From: zhuo-hao
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
This was noticed because the HPET RTC emulation fires an interrupt every
16ms(=1/2^DEFAULT_RTC_SHIFT) up to the point where the alarm time is reached.
This program always hits this situation(https://lkml.org/lkml/2015/11/8/326),
if system wake up earlier than alarm time.
Cc: Thomas Gleixner
Cc: John Stultz
Signed-off-by: Zhuo-hao Lee
---
kernel/time/alarmtimer.c | 17 +
1 file changed, 17 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..e840ed8 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,27 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ if (rtc)
+ rtc_timer_cancel(rtc, );
+ return 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +816,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
2.1.2
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3] alarmtimer: fix unexpected rtc interrupt when system resume from S3
From: zhuo-hao <zhuo-hao@intel.com>
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
This was noticed because the HPET RTC emulation fires an interrupt every
16ms(=1/2^DEFAULT_RTC_SHIFT) up to the point where the alarm time is reached.
This program always hits this situation(https://lkml.org/lkml/2015/11/8/326),
if system wake up earlier than alarm time.
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: John Stultz <john.stu...@linaro.org>
Signed-off-by: Zhuo-hao Lee <zhuo-hao@intel.com>
---
kernel/time/alarmtimer.c | 17 +
1 file changed, 17 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..e840ed8 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,27 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ if (rtc)
+ rtc_timer_cancel(rtc, );
+ return 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +816,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
2.1.2
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2] alarmtimer: fix unexpected rtc interrupt when system resume from S3
From: zhuo-hao
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
Signed-off-by: Zhuo-hao Lee
---
kernel/time/alarmtimer.c | 17 +
1 file changed, 17 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..e840ed8 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,27 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ if (rtc)
+ rtc_timer_cancel(rtc, );
+ return 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +816,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
1.9.1
--
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the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH] alarmtimer: fix unexpected rtc interrupt when system resume
From: zhuo-hao
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
Signed-off-by: Zhuo-hao Lee
---
kernel/time/alarmtimer.c | 15 +++
1 file changed, 15 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..37ffccd 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,25 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ return rtc ? rtc_timer_cancel(rtc, ) : 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +814,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
1.9.1
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH] alarmtimer: fix unexpected rtc interrupt when system resume
From: zhuo-hao <zhuo-hao@intel.com>
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
Signed-off-by: Zhuo-hao Lee <zhuo-hao@intel.com>
---
kernel/time/alarmtimer.c | 15 +++
1 file changed, 15 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..37ffccd 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,25 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ return rtc ? rtc_timer_cancel(rtc, ) : 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +814,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2] alarmtimer: fix unexpected rtc interrupt when system resume from S3
From: zhuo-hao <zhuo-hao@intel.com>
Before the system go to suspend (S3), if user create a timer with clockid
CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value
to this timer. The function alarmtimer_suspend will be called to setup
a timeout value to RTC timer to avoid the system sleep over time. However,
if the system wakeup early than RTC timeout, the RTC timer will not be cleared.
And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC
timeout. To fix this problem, just adding alarmtimer_resume to cancel the
RTC timer.
Signed-off-by: Zhuo-hao Lee <zhuo-hao@intel.com>
---
kernel/time/alarmtimer.c | 17 +
1 file changed, 17 insertions(+)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7fbba63..e840ed8 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -271,11 +271,27 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ struct rtc_device *rtc;
+
+ rtc = alarmtimer_get_rtcdev();
+ if (rtc)
+ rtc_timer_cancel(rtc, );
+ return 0;
+}
+
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
+
+static int alarmtimer_resume(struct device *dev)
+{
+ return 0;
+}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@@ -800,6 +816,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
+ .resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {
--
1.9.1
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
