Hi Raffaele,
On Monday 29 October 2012 04:41 PM, Raffaele Recalcati wrote:
In NOWAYOUT case it is better to have watchdog always enabled at boot,
in order not to leave the system in undefined state in case of userspace
failure.
Signed-off-by: Raffaele Recalcati <[email protected]>
---
Tested using http://arago-project.org/git/projects/linux-omap3.git
v2.6.37_OMAPPSP_04.02.00.07 commit.
drivers/watchdog/omap_wdt.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
index 27ab8db..181b939 100644
--- a/drivers/watchdog/omap_wdt.c
+++ b/drivers/watchdog/omap_wdt.c
@@ -304,8 +304,16 @@ static int __devinit omap_wdt_probe(struct platform_device
*pdev)
pm_runtime_enable(wdev->dev);
pm_runtime_get_sync(wdev->dev);
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
omap_wdt_disable(wdev);
omap_wdt_adjust_timeout(timer_margin);
+#else
+ omap_wdt_adjust_timeout(timer_margin);
+ omap_wdt_disable(wdev);
+ omap_wdt_set_timeout(wdev);
+ omap_wdt_enable(wdev);
+ omap_wdt_ping(wdev);
IMHO this is not the correct procedure to start the watchdog.
The sequence to start watchdog is something similar in omap_wdt_open()
the steps are:
1) Increment omap_wdt_users
2) Set prescalar value
3) Enable prescalar value
4) Load timer counter value
5) Enable watchdog timer.
In your case you are missing first 3 steps.
After starting the watchdog, there should be some daemon
which pets the watchdog before timeout, if not it will reset the board.
This is also missing in your case.
( This daemon can be achieved by enabling delay interrupt and period)
And there is a pm_runtime_put_sync after you enable your watchdog.
Because of which you get the following warning
omap_hwmod: wd_timer2: _wait_target_disable failed
Below is the patch which might meet your aims.
Please comment on the patch.
Here I enabled delay interrupt and delay period
for petting watchdog before timeout.
watchdog is enabled for all the cases(not only for NOWAYOUT)
Signed-off-by: Lokesh Vutla <[email protected]>
---
drivers/watchdog/omap_wdt.c | 82
++++++++++++++++++++++++++++++++++++++++-----
drivers/watchdog/omap_wdt.h | 4 +++
2 files changed, 78 insertions(+), 8 deletions(-)
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
index f5db18db..38e36c1 100644
--- a/drivers/watchdog/omap_wdt.c
+++ b/drivers/watchdog/omap_wdt.c
@@ -45,6 +45,7 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
+#include <linux/interrupt.h>
#include <mach/hardware.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
@@ -57,6 +58,10 @@ static unsigned timer_margin;
module_param(timer_margin, uint, 0);
MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
+static int kernelpet = 1;
+module_param(kernelpet, int, 0);
+MODULE_PARM_DESC(kernelpet, "pet watchdog in kernel via irq");
+
static unsigned int wdt_trgr_pattern = 0x1234;
static DEFINE_SPINLOCK(wdt_lock);
@@ -66,6 +71,7 @@ struct omap_wdt_dev {
int omap_wdt_users;
struct resource *mem;
struct miscdevice omap_wdt_miscdev;
+ int irq;
};
static void omap_wdt_ping(struct omap_wdt_dev *wdev)
@@ -125,6 +131,7 @@ static void omap_wdt_adjust_timeout(unsigned
new_timeout)
static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
{
u32 pre_margin = GET_WLDR_VAL(timer_margin);
+ u32 delay_period = GET_WLDR_VAL(timer_margin / 2);
void __iomem *base = wdev->base;
/* just count up at 32 KHz */
@@ -134,14 +141,29 @@ static void omap_wdt_set_timeout(struct
omap_wdt_dev *wdev)
__raw_writel(pre_margin, base + OMAP_WATCHDOG_LDR);
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
cpu_relax();
+
+ /* Set delay interrupt to half the watchdog interval. */
+ while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 1 << 5)
+ cpu_relax();
+ __raw_writel(delay_period, base + OMAP_WATCHDOG_WDLY);
}
-/*
- * Allow only one task to hold it open
- */
-static int omap_wdt_open(struct inode *inode, struct file *file)
+static irqreturn_t omap_wdt_interrupt(int irq, void *dev_id)
+{
+ struct omap_wdt_dev *wdev = dev_id;
+ void __iomem *base = wdev->base;
+ u32 i;
+
+ i = __raw_readl(base + OMAP_WATCHDOG_WIRQSTAT);
+ __raw_writel(i, base + OMAP_WATCHDOG_WIRQSTAT);
+
+ omap_wdt_ping(wdev);
+
+ return IRQ_HANDLED;
+}
+
+static int omap_wdt_setup(struct omap_wdt_dev *wdev)
{
- struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
void __iomem *base = wdev->base;
if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
@@ -157,12 +179,31 @@ static int omap_wdt_open(struct inode *inode,
struct file *file)
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
cpu_relax();
- file->private_data = (void *) wdev;
-
omap_wdt_set_timeout(wdev);
omap_wdt_ping(wdev); /* trigger loading of new timeout value */
+
+ /* Enable delay interrupt */
+ if (kernelpet && wdev->irq)
+ __raw_writel(0x2, base + OMAP_WATCHDOG_WIRQENSET);
+
omap_wdt_enable(wdev);
+ return 0;
+}
+/*
+ * Allow only one task to hold it open
+ */
+static int omap_wdt_open(struct inode *inode, struct file *file)
+{
+ struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
+ int ret;
+
+ ret = omap_wdt_setup(wdev);
+
+ if (ret)
+ return ret;
+
+ file->private_data = (void *)wdev;
return nonseekable_open(inode, file);
}
@@ -176,6 +217,10 @@ static int omap_wdt_release(struct inode *inode,
struct file *file)
#ifndef CONFIG_WATCHDOG_NOWAYOUT
omap_wdt_disable(wdev);
+ /* Disable delay interrupt */
+ if (kernelpet && wdev->irq)
+ __raw_writel(0x2, base + OMAP_WATCHDOG_WIRQENCLR);
+
pm_runtime_put_sync(wdev->dev);
#else
pr_crit("Unexpected close, not stopping!\n");
@@ -266,7 +311,7 @@ static const struct file_operations omap_wdt_fops = {
static int __devinit omap_wdt_probe(struct platform_device *pdev)
{
- struct resource *res, *mem;
+ struct resource *res, *mem, *res_irq;
struct omap_wdt_dev *wdev;
int ret;
@@ -288,6 +333,8 @@ static int __devinit omap_wdt_probe(struct
platform_device *pdev)
goto err_busy;
}
+ res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+
wdev = kzalloc(sizeof(struct omap_wdt_dev), GFP_KERNEL);
if (!wdev) {
ret = -ENOMEM;
@@ -304,6 +351,16 @@ static int __devinit omap_wdt_probe(struct
platform_device *pdev)
goto err_ioremap;
}
+ if (res_irq) {
+ ret = request_irq(res_irq->start, omap_wdt_interrupt, 0,
+ dev_name(&pdev->dev), wdev);
+
+ if (ret)
+ goto err_irq;
+
+ wdev->irq = res_irq->start;
+ }
+
platform_set_drvdata(pdev, wdev);
pm_runtime_enable(wdev->dev);
@@ -329,11 +386,17 @@ static int __devinit omap_wdt_probe(struct
platform_device *pdev)
omap_wdt_dev = pdev;
+ if (kernelpet && wdev->irq)
+ return omap_wdt_setup(wdev);
+
return 0;
err_misc:
pm_runtime_disable(wdev->dev);
platform_set_drvdata(pdev, NULL);
+ if (wdev->irq)
+ free_irq(wdev->irq, wdev);
+err_irq:
iounmap(wdev->base);
err_ioremap:
@@ -372,6 +435,9 @@ static int __devexit omap_wdt_remove(struct
platform_device *pdev)
release_mem_region(res->start, resource_size(res));
platform_set_drvdata(pdev, NULL);
+ if (wdev->irq)
+ free_irq(wdev->irq, wdev);
+
iounmap(wdev->base);
kfree(wdev);
diff --git a/drivers/watchdog/omap_wdt.h b/drivers/watchdog/omap_wdt.h
index 09b774c..c9980d3 100644
--- a/drivers/watchdog/omap_wdt.h
+++ b/drivers/watchdog/omap_wdt.h
@@ -38,7 +38,11 @@
#define OMAP_WATCHDOG_LDR (0x2c)
#define OMAP_WATCHDOG_TGR (0x30)
#define OMAP_WATCHDOG_WPS (0x34)
+#define OMAP_WATCHDOG_WDLY (0x44)
#define OMAP_WATCHDOG_SPR (0x48)
+#define OMAP_WATCHDOG_WIRQSTAT (0x58)
+#define OMAP_WATCHDOG_WIRQENSET (0x5c)
+#define OMAP_WATCHDOG_WIRQENCLR (0x60)
/* Using the prescaler, the OMAP watchdog could go for many
* months before firing. These limits work without scaling,
--
Thanks
Lokesh
+#endif
wdev->omap_wdt_miscdev.parent = &pdev->dev;
wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR;
--
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