* [PATCH V2] watchdog: mtk: support pre-timeout when the bark irq is available
@ 2021-04-14 7:28 Wang Qing
2021-04-14 11:23 ` Guenter Roeck
0 siblings, 1 reply; 2+ messages in thread
From: Wang Qing @ 2021-04-14 7:28 UTC (permalink / raw)
To: Wim Van Sebroeck, Guenter Roeck, Matthias Brugger,
linux-watchdog, linux-arm-kernel, linux-mediatek, linux-kernel
Cc: Wang Qing
Use the bark interrupt as the pretimeout notifier if available.
By default, the pretimeout notification shall occur one second earlier
than the timeout.
V2:
- panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled
Signed-off-by: Wang Qing <wangqing@vivo.com>
---
drivers/watchdog/mtk_wdt.c | 57 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 52 insertions(+), 5 deletions(-)
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 97ca993..b0ec933
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -25,6 +25,7 @@
#include <linux/reset-controller.h>
#include <linux/types.h>
#include <linux/watchdog.h>
+#include <linux/interrupt.h>
#define WDT_MAX_TIMEOUT 31
#define WDT_MIN_TIMEOUT 1
@@ -234,18 +235,41 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
void __iomem *wdt_base = mtk_wdt->wdt_base;
int ret;
- ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+ ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout - wdt_dev->pretimeout);
if (ret < 0)
return ret;
reg = ioread32(wdt_base + WDT_MODE);
- reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+ reg &= ~WDT_MODE_IRQ_EN;
+ if (wdt_dev->pretimeout)
+ reg |= WDT_MODE_IRQ_EN;
+ else
+ reg &= ~WDT_MODE_IRQ_EN;
reg |= (WDT_MODE_EN | WDT_MODE_KEY);
iowrite32(reg, wdt_base + WDT_MODE);
return 0;
}
+static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ wdd->pretimeout = timeout;
+ return mtk_wdt_start(wdd);
+}
+
+static irqreturn_t mtk_wdt_isr(int irq, void *arg)
+{
+ struct watchdog_device *wdd = arg;
+if (IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV))
+ watchdog_notify_pretimeout(wdd);
+else
+ //panic by decault instead of WDT_SWRST;
+ panic("MTk Watchdog bark!\n");
+
+ return IRQ_HANDLED;
+}
+
static const struct watchdog_info mtk_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT |
@@ -253,12 +277,21 @@ static const struct watchdog_info mtk_wdt_info = {
WDIOF_MAGICCLOSE,
};
+static const struct watchdog_info mtk_wdt_pt_info = {
+ .identity = DRV_NAME,
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_PRETIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
static const struct watchdog_ops mtk_wdt_ops = {
.owner = THIS_MODULE,
.start = mtk_wdt_start,
.stop = mtk_wdt_stop,
.ping = mtk_wdt_ping,
.set_timeout = mtk_wdt_set_timeout,
+ .set_pretimeout = mtk_wdt_set_pretimeout,
.restart = mtk_wdt_restart,
};
@@ -267,7 +300,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct mtk_wdt_dev *mtk_wdt;
const struct mtk_wdt_data *wdt_data;
- int err;
+ int err, irq;
mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
if (!mtk_wdt)
@@ -279,7 +312,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
if (IS_ERR(mtk_wdt->wdt_base))
return PTR_ERR(mtk_wdt->wdt_base);
- mtk_wdt->wdt_dev.info = &mtk_wdt_info;
+ irq = platform_get_irq(pdev, 0);
+ if (irq > 0) {
+ err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
+ &mtk_wdt->wdt_dev);
+ if (err)
+ return err;
+
+ mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
+ mtk_wdt->wdt_dev.pretimeout = 1;
+ } else {
+ if (irq == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ mtk_wdt->wdt_dev.info = &mtk_wdt_info;
+ }
+
mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
@@ -360,7 +408,6 @@ static struct platform_driver mtk_wdt_driver = {
};
module_platform_driver(mtk_wdt_driver);
-
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2] watchdog: mtk: support pre-timeout when the bark irq is available
2021-04-14 7:28 [PATCH V2] watchdog: mtk: support pre-timeout when the bark irq is available Wang Qing
@ 2021-04-14 11:23 ` Guenter Roeck
0 siblings, 0 replies; 2+ messages in thread
From: Guenter Roeck @ 2021-04-14 11:23 UTC (permalink / raw)
To: Wang Qing, Wim Van Sebroeck, Matthias Brugger, linux-watchdog,
linux-arm-kernel, linux-mediatek, linux-kernel
On 4/14/21 12:28 AM, Wang Qing wrote:
> Use the bark interrupt as the pretimeout notifier if available.
>
> By default, the pretimeout notification shall occur one second earlier
> than the timeout.
>
> V2:
> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled
>
> Signed-off-by: Wang Qing <wangqing@vivo.com>
> ---
> drivers/watchdog/mtk_wdt.c | 57 ++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 52 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index 97ca993..b0ec933
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -25,6 +25,7 @@
> #include <linux/reset-controller.h>
> #include <linux/types.h>
> #include <linux/watchdog.h>
> +#include <linux/interrupt.h>
>
> #define WDT_MAX_TIMEOUT 31
> #define WDT_MIN_TIMEOUT 1
> @@ -234,18 +235,41 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
> void __iomem *wdt_base = mtk_wdt->wdt_base;
> int ret;
>
> - ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
> + ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout - wdt_dev->pretimeout);
> if (ret < 0)
> return ret;
>
> reg = ioread32(wdt_base + WDT_MODE);
> - reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> + reg &= ~WDT_MODE_IRQ_EN;
> + if (wdt_dev->pretimeout)
> + reg |= WDT_MODE_IRQ_EN;
> + else
> + reg &= ~WDT_MODE_IRQ_EN;
> reg |= (WDT_MODE_EN | WDT_MODE_KEY);
> iowrite32(reg, wdt_base + WDT_MODE);
>
You said previously that the pretimeout would prevent the real timeout / reset
from happening, and the driver has no provision to set the real timeout.
That makes this a no-go.
> return 0;
> }
>
> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
> + unsigned int timeout)
> +{
> + wdd->pretimeout = timeout;
> + return mtk_wdt_start(wdd);
> +}
> +
> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
> +{
> + struct watchdog_device *wdd = arg;
> +if (IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV))
> + watchdog_notify_pretimeout(wdd);
> +else
> + //panic by decault instead of WDT_SWRST;
> + panic("MTk Watchdog bark!\n");
> +
The idea behind the pretimeout governor is that it can be disabled
by setting it to "none", and if pretimeout governors are disabled
it is supposed to be a no-op. The above bypasses this mechanism
and is not acceptable.
This suggests that the real timeout indeed doesn't happen when
WDT_MODE_IRQ_EN is set. Again, this is unacceptable.
On a side note, formatting is way off here.
Guenter
> + return IRQ_HANDLED;
> +}
> +
> static const struct watchdog_info mtk_wdt_info = {
> .identity = DRV_NAME,
> .options = WDIOF_SETTIMEOUT |
> @@ -253,12 +277,21 @@ static const struct watchdog_info mtk_wdt_info = {
> WDIOF_MAGICCLOSE,
> };
>
> +static const struct watchdog_info mtk_wdt_pt_info = {
> + .identity = DRV_NAME,
> + .options = WDIOF_SETTIMEOUT |
> + WDIOF_PRETIMEOUT |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_MAGICCLOSE,
> +};
> +
> static const struct watchdog_ops mtk_wdt_ops = {
> .owner = THIS_MODULE,
> .start = mtk_wdt_start,
> .stop = mtk_wdt_stop,
> .ping = mtk_wdt_ping,
> .set_timeout = mtk_wdt_set_timeout,
> + .set_pretimeout = mtk_wdt_set_pretimeout,
> .restart = mtk_wdt_restart,
> };
>
> @@ -267,7 +300,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct mtk_wdt_dev *mtk_wdt;
> const struct mtk_wdt_data *wdt_data;
> - int err;
> + int err, irq;
>
> mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
> if (!mtk_wdt)
> @@ -279,7 +312,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> if (IS_ERR(mtk_wdt->wdt_base))
> return PTR_ERR(mtk_wdt->wdt_base);
>
> - mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> + irq = platform_get_irq(pdev, 0);
> + if (irq > 0) {
> + err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
> + &mtk_wdt->wdt_dev);
> + if (err)
> + return err;
> +
> + mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
> + mtk_wdt->wdt_dev.pretimeout = 1;
> + } else {
> + if (irq == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> +
> + mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> + }
> +
> mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
> mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
> mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
> @@ -360,7 +408,6 @@ static struct platform_driver mtk_wdt_driver = {
> };
>
> module_platform_driver(mtk_wdt_driver);
> -
> module_param(timeout, uint, 0);
> MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-04-14 11:23 ` Guenter Roeck
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