| Message ID | 1618385339-3527-1-git-send-email-wangqing@vivo.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [V2] watchdog: mtk: support pre-timeout when the bark irq is available | expand |
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"); > >
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");
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(-)