* [PATCH 0/3] getting more output from orion_wdt
@ 2017-10-11 2:29 Chris Packham
2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham
` (2 more replies)
0 siblings, 3 replies; 19+ messages in thread
From: Chris Packham @ 2017-10-11 2:29 UTC (permalink / raw)
To: linux, wim, gregory.clement, devicetree, linux-watchdog
Cc: linux-kernel, Chris Packham
On the Armada-38x platforms (and probably 37x/XP) the current behaviour of on
exipry of the watchdog is a silent reboot of the CPU. The Armada-38x does have
an interrupt which if we don't enable the Global WD bit in the RSTOUTn register
gives us a chance to generate some panic messages that may help track down the
cause of the watchdog timeout.
I've been a bit bold and enabled this in the generic armada-38x.dtsi file. I'd
be happy to leave that part out and have the interrupt enabled on a
board-by-board basis if there are objections.
Chris Packham (3):
watchdog: orion: fix typo
watchdog: orion: don't enable rstout if an interrupt is configured
ARM: mvebu: dts: connect interrupt for WD on armada-38x
arch/arm/boot/dts/armada-38x.dtsi | 1 +
drivers/watchdog/orion_wdt.c | 27 ++++++++++++++++++---------
2 files changed, 19 insertions(+), 9 deletions(-)
--
2.14.2
^ permalink raw reply [flat|nested] 19+ messages in thread* [PATCH 1/3] watchdog: orion: fix typo 2017-10-11 2:29 [PATCH 0/3] getting more output from orion_wdt Chris Packham @ 2017-10-11 2:29 ` Chris Packham 2017-10-11 3:35 ` Guenter Roeck 2017-10-11 2:29 ` [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured Chris Packham 2017-10-11 2:29 ` [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x Chris Packham 2 siblings, 1 reply; 19+ messages in thread From: Chris Packham @ 2017-10-11 2:29 UTC (permalink / raw) To: linux, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel, Chris Packham Correct typo in comment "insterted" -> "inserted". Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- drivers/watchdog/orion_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index 83af7d6cc37c..ea676d233e1e 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -576,7 +576,7 @@ static int orion_wdt_probe(struct platform_device *pdev) /* * Let's make sure the watchdog is fully stopped, unless it's * explicitly enabled. This may be the case if the module was - * removed and re-insterted, or if the bootloader explicitly + * removed and re-inserted, or if the bootloader explicitly * set a running watchdog before booting the kernel. */ if (!orion_wdt_enabled(&dev->wdt)) -- 2.14.2 ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 1/3] watchdog: orion: fix typo 2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham @ 2017-10-11 3:35 ` Guenter Roeck 0 siblings, 0 replies; 19+ messages in thread From: Guenter Roeck @ 2017-10-11 3:35 UTC (permalink / raw) To: Chris Packham, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel On 10/10/2017 07:29 PM, Chris Packham wrote: > Correct typo in comment "insterted" -> "inserted". > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/orion_wdt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c > index 83af7d6cc37c..ea676d233e1e 100644 > --- a/drivers/watchdog/orion_wdt.c > +++ b/drivers/watchdog/orion_wdt.c > @@ -576,7 +576,7 @@ static int orion_wdt_probe(struct platform_device *pdev) > /* > * Let's make sure the watchdog is fully stopped, unless it's > * explicitly enabled. This may be the case if the module was > - * removed and re-insterted, or if the bootloader explicitly > + * removed and re-inserted, or if the bootloader explicitly > * set a running watchdog before booting the kernel. > */ > if (!orion_wdt_enabled(&dev->wdt)) > ^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured 2017-10-11 2:29 [PATCH 0/3] getting more output from orion_wdt Chris Packham 2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham @ 2017-10-11 2:29 ` Chris Packham 2017-10-11 3:41 ` Guenter Roeck 2017-10-11 2:29 ` [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x Chris Packham 2 siblings, 1 reply; 19+ messages in thread From: Chris Packham @ 2017-10-11 2:29 UTC (permalink / raw) To: linux, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel, Chris Packham The orion_wdt_irq invokes panic() so we are going to reset the CPU regardless. By not setting this bit we get a chance to gather debug from the panic output before the system is reset. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- drivers/watchdog/orion_wdt.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index ea676d233e1e..ce88f339ef7f 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -71,6 +71,7 @@ struct orion_watchdog { unsigned long clk_rate; struct clk *clk; const struct orion_watchdog_data *data; + int irq; }; static int orion_wdt_clock_init(struct platform_device *pdev, @@ -203,9 +204,11 @@ static int armada375_start(struct watchdog_device *wdt_dev) dev->data->wdt_enable_bit); /* Enable reset on watchdog */ - reg = readl(dev->rstout); - reg |= dev->data->rstout_enable_bit; - writel(reg, dev->rstout); + if (!dev->irq) { + reg = readl(dev->rstout); + reg |= dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + } atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0); return 0; @@ -228,9 +231,12 @@ static int armada370_start(struct watchdog_device *wdt_dev) dev->data->wdt_enable_bit); /* Enable reset on watchdog */ - reg = readl(dev->rstout); - reg |= dev->data->rstout_enable_bit; - writel(reg, dev->rstout); + if (!dev->irq) { + reg = readl(dev->rstout); + reg |= dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + } + return 0; } @@ -247,8 +253,9 @@ static int orion_start(struct watchdog_device *wdt_dev) dev->data->wdt_enable_bit); /* Enable reset on watchdog */ - atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, - dev->data->rstout_enable_bit); + if (!dev->irq) + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, + dev->data->rstout_enable_bit); return 0; } @@ -595,6 +602,8 @@ static int orion_wdt_probe(struct platform_device *pdev) dev_err(&pdev->dev, "failed to request IRQ\n"); goto disable_clk; } + + dev->irq = irq; } watchdog_set_nowayout(&dev->wdt, nowayout); -- 2.14.2 ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured 2017-10-11 2:29 ` [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured Chris Packham @ 2017-10-11 3:41 ` Guenter Roeck 2017-10-11 4:30 ` Chris Packham 0 siblings, 1 reply; 19+ messages in thread From: Guenter Roeck @ 2017-10-11 3:41 UTC (permalink / raw) To: Chris Packham, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel On 10/10/2017 07:29 PM, Chris Packham wrote: > The orion_wdt_irq invokes panic() so we are going to reset the CPU > regardless. By not setting this bit we get a chance to gather debug > from the panic output before the system is reset. > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Unless I am missing something, this assumes that the interrupt is handled, ie that the system is not stuck with interrupts disabled. This makes the watchdog less reliable. This added verbosity comes at a significant cost. I'd like to get input from others if this is acceptable. That would be different if there was a means to configure a pretimeout, ie a means to tell the system to generate an irq first, followed by a hard reset if the interrupt is not served. that does not seem to be the case here, though. Guenter > --- > drivers/watchdog/orion_wdt.c | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c > index ea676d233e1e..ce88f339ef7f 100644 > --- a/drivers/watchdog/orion_wdt.c > +++ b/drivers/watchdog/orion_wdt.c > @@ -71,6 +71,7 @@ struct orion_watchdog { > unsigned long clk_rate; > struct clk *clk; > const struct orion_watchdog_data *data; > + int irq; > }; > > static int orion_wdt_clock_init(struct platform_device *pdev, > @@ -203,9 +204,11 @@ static int armada375_start(struct watchdog_device *wdt_dev) > dev->data->wdt_enable_bit); > > /* Enable reset on watchdog */ > - reg = readl(dev->rstout); > - reg |= dev->data->rstout_enable_bit; > - writel(reg, dev->rstout); > + if (!dev->irq) { > + reg = readl(dev->rstout); > + reg |= dev->data->rstout_enable_bit; > + writel(reg, dev->rstout); > + } > > atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0); > return 0; > @@ -228,9 +231,12 @@ static int armada370_start(struct watchdog_device *wdt_dev) > dev->data->wdt_enable_bit); > > /* Enable reset on watchdog */ > - reg = readl(dev->rstout); > - reg |= dev->data->rstout_enable_bit; > - writel(reg, dev->rstout); > + if (!dev->irq) { > + reg = readl(dev->rstout); > + reg |= dev->data->rstout_enable_bit; > + writel(reg, dev->rstout); > + } > + > return 0; > } > > @@ -247,8 +253,9 @@ static int orion_start(struct watchdog_device *wdt_dev) > dev->data->wdt_enable_bit); > > /* Enable reset on watchdog */ > - atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, > - dev->data->rstout_enable_bit); > + if (!dev->irq) > + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, > + dev->data->rstout_enable_bit); > > return 0; > } > @@ -595,6 +602,8 @@ static int orion_wdt_probe(struct platform_device *pdev) > dev_err(&pdev->dev, "failed to request IRQ\n"); > goto disable_clk; > } > + > + dev->irq = irq; > } > > watchdog_set_nowayout(&dev->wdt, nowayout); > ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured 2017-10-11 3:41 ` Guenter Roeck @ 2017-10-11 4:30 ` Chris Packham 2019-02-27 20:59 ` Chris Packham 0 siblings, 1 reply; 19+ messages in thread From: Chris Packham @ 2017-10-11 4:30 UTC (permalink / raw) To: Guenter Roeck, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel On 11/10/17 16:42, Guenter Roeck wrote: > On 10/10/2017 07:29 PM, Chris Packham wrote: >> The orion_wdt_irq invokes panic() so we are going to reset the CPU >> regardless. By not setting this bit we get a chance to gather debug >> from the panic output before the system is reset. >> >> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > > Unless I am missing something, this assumes that the interrupt is > handled, ie that the system is not stuck with interrupts disabled. > This makes the watchdog less reliable. This added verbosity comes > at a significant cost. I'd like to get input from others if this > is acceptable. > > That would be different if there was a means to configure a pretimeout, > ie a means to tell the system to generate an irq first, followed by a > hard reset if the interrupt is not served. that does not seem to be > the case here, though. > As far as I can tell there is no pretimeout capability in the orion /armada WDT. I have got a work-in-progress patch that enables the RSTOUT in the interrupt handler which some-what mitigates your concern but still requires the interrupt to be handled at least once. Another option would be to use one of the spare global timers to provide the interrupt-driven aspect. Of course if the irq isn't specified then the existing behaviour is retained which would make the 3/3 patch of this series the debatable part. > Guenter > >> --- >> drivers/watchdog/orion_wdt.c | 25 +++++++++++++++++-------- >> 1 file changed, 17 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c >> index ea676d233e1e..ce88f339ef7f 100644 >> --- a/drivers/watchdog/orion_wdt.c >> +++ b/drivers/watchdog/orion_wdt.c >> @@ -71,6 +71,7 @@ struct orion_watchdog { >> unsigned long clk_rate; >> struct clk *clk; >> const struct orion_watchdog_data *data; >> + int irq; >> }; >> >> static int orion_wdt_clock_init(struct platform_device *pdev, >> @@ -203,9 +204,11 @@ static int armada375_start(struct watchdog_device *wdt_dev) >> dev->data->wdt_enable_bit); >> >> /* Enable reset on watchdog */ >> - reg = readl(dev->rstout); >> - reg |= dev->data->rstout_enable_bit; >> - writel(reg, dev->rstout); >> + if (!dev->irq) { >> + reg = readl(dev->rstout); >> + reg |= dev->data->rstout_enable_bit; >> + writel(reg, dev->rstout); >> + } >> >> atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0); >> return 0; >> @@ -228,9 +231,12 @@ static int armada370_start(struct watchdog_device *wdt_dev) >> dev->data->wdt_enable_bit); >> >> /* Enable reset on watchdog */ >> - reg = readl(dev->rstout); >> - reg |= dev->data->rstout_enable_bit; >> - writel(reg, dev->rstout); >> + if (!dev->irq) { >> + reg = readl(dev->rstout); >> + reg |= dev->data->rstout_enable_bit; >> + writel(reg, dev->rstout); >> + } >> + >> return 0; >> } >> >> @@ -247,8 +253,9 @@ static int orion_start(struct watchdog_device *wdt_dev) >> dev->data->wdt_enable_bit); >> >> /* Enable reset on watchdog */ >> - atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, >> - dev->data->rstout_enable_bit); >> + if (!dev->irq) >> + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, >> + dev->data->rstout_enable_bit); >> >> return 0; >> } >> @@ -595,6 +602,8 @@ static int orion_wdt_probe(struct platform_device *pdev) >> dev_err(&pdev->dev, "failed to request IRQ\n"); >> goto disable_clk; >> } >> + >> + dev->irq = irq; >> } >> >> watchdog_set_nowayout(&dev->wdt, nowayout); >> > > ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured 2017-10-11 4:30 ` Chris Packham @ 2019-02-27 20:59 ` Chris Packham 2019-02-27 23:07 ` Guenter Roeck 0 siblings, 1 reply; 19+ messages in thread From: Chris Packham @ 2019-02-27 20:59 UTC (permalink / raw) To: Guenter Roeck, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel Hijacking an old thread, On 11/10/17 5:30 PM, Chris Packham wrote: > On 11/10/17 16:42, Guenter Roeck wrote: >> On 10/10/2017 07:29 PM, Chris Packham wrote: >>> The orion_wdt_irq invokes panic() so we are going to reset the CPU >>> regardless. By not setting this bit we get a chance to gather debug >>> from the panic output before the system is reset. >>> >>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> >> >> Unless I am missing something, this assumes that the interrupt is >> handled, ie that the system is not stuck with interrupts disabled. >> This makes the watchdog less reliable. This added verbosity comes >> at a significant cost. I'd like to get input from others if this >> is acceptable. >> >> That would be different if there was a means to configure a pretimeout, >> ie a means to tell the system to generate an irq first, followed by a >> hard reset if the interrupt is not served. that does not seem to be >> the case here, though. >> > > As far as I can tell there is no pretimeout capability in the orion > /armada WDT. I have got a work-in-progress patch that enables the RSTOUT > in the interrupt handler which some-what mitigates your concern but > still requires the interrupt to be handled at least once. > > Another option would be to use one of the spare global timers to provide > the interrupt-driven aspect. So as Guenter rightly pointed out my original patch meant that we'd hang if we got stuck in a loop with interrupts disabled. Shortly after that that's exactly what happened on my test setup. I've now been able to follow-up on the idea of using one of the spare global timers as a pretimeout indication and it's looking pretty promising. The patch is below (beware MUA wrapping). I'll submit it properly but I'm wondering if I should add the timer1 based watchdog as a separate watchdog device or like I have below roll it into the existing watchdog device. --- 8< --- diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi index 8530d3594ca2..abd45adb4728 100644 --- a/arch/arm/boot/dts/armada-38x.dtsi +++ b/arch/arm/boot/dts/armada-38x.dtsi @@ -421,6 +421,7 @@ reg = <0x20300 0x34>, <0x20704 0x4>, <0x18260 0x4>; clocks = <&coreclk 2>, <&refclk>; clock-names = "nbclk", "fixed"; + interrupts-extended = <&gic GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>; }; cpurst: cpurst@20800 { diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index c6b8f4a43bde..89eae53b1b17 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -37,13 +37,16 @@ #define TIMER_CTRL 0x0000 #define TIMER_A370_STATUS 0x04 +#define TIMER1_RELOAD_OFF 0x0018 +#define TIMER1_VAL_OFF 0x001c + #define WDT_MAX_CYCLE_COUNT 0xffffffff #define WDT_A370_RATIO_MASK(v) ((v) << 16) #define WDT_A370_RATIO_SHIFT 5 #define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT) -#define WDT_AXP_FIXED_ENABLE_BIT BIT(10) +#define WDT_AXP_FIXED_ENABLE_BIT BIT(10) | BIT(12) #define WDT_A370_EXPIRED BIT(31) static bool nowayout = WATCHDOG_NOWAYOUT; @@ -183,6 +186,9 @@ static int orion_wdt_ping(struct watchdog_device *wdt_dev) /* Reload watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + dev->data->wdt_counter_offset); + writel(dev->clk_rate * (wdt_dev->timeout/2), + dev->reg + TIMER1_VAL_OFF); + return 0; } @@ -194,6 +200,8 @@ static int armada375_start(struct watchdog_device *wdt_dev) /* Set watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + dev->data->wdt_counter_offset); + writel(dev->clk_rate * (wdt_dev->timeout/2), + dev->reg + TIMER1_VAL_OFF); /* Clear the watchdog expiration bit */ atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0); @@ -443,7 +451,7 @@ static const struct orion_watchdog_data armada375_data = { static const struct orion_watchdog_data armada380_data = { .rstout_enable_bit = BIT(8), .rstout_mask_bit = BIT(10), - .wdt_enable_bit = BIT(8), + .wdt_enable_bit = BIT(8) | BIT(2), .wdt_counter_offset = 0x34, .clock_init = armadaxp_wdt_clock_init, .enabled = armada375_enabled, --- 8< --- > > Of course if the irq isn't specified then the existing behaviour is > retained which would make the 3/3 patch of this series the debatable part. > > >> Guenter >> >>> --- >>> drivers/watchdog/orion_wdt.c | 25 +++++++++++++++++-------- >>> 1 file changed, 17 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c >>> index ea676d233e1e..ce88f339ef7f 100644 >>> --- a/drivers/watchdog/orion_wdt.c >>> +++ b/drivers/watchdog/orion_wdt.c >>> @@ -71,6 +71,7 @@ struct orion_watchdog { >>> unsigned long clk_rate; >>> struct clk *clk; >>> const struct orion_watchdog_data *data; >>> + int irq; >>> }; >>> >>> static int orion_wdt_clock_init(struct platform_device *pdev, >>> @@ -203,9 +204,11 @@ static int armada375_start(struct watchdog_device *wdt_dev) >>> dev->data->wdt_enable_bit); >>> >>> /* Enable reset on watchdog */ >>> - reg = readl(dev->rstout); >>> - reg |= dev->data->rstout_enable_bit; >>> - writel(reg, dev->rstout); >>> + if (!dev->irq) { >>> + reg = readl(dev->rstout); >>> + reg |= dev->data->rstout_enable_bit; >>> + writel(reg, dev->rstout); >>> + } >>> >>> atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0); >>> return 0; >>> @@ -228,9 +231,12 @@ static int armada370_start(struct watchdog_device *wdt_dev) >>> dev->data->wdt_enable_bit); >>> >>> /* Enable reset on watchdog */ >>> - reg = readl(dev->rstout); >>> - reg |= dev->data->rstout_enable_bit; >>> - writel(reg, dev->rstout); >>> + if (!dev->irq) { >>> + reg = readl(dev->rstout); >>> + reg |= dev->data->rstout_enable_bit; >>> + writel(reg, dev->rstout); >>> + } >>> + >>> return 0; >>> } >>> >>> @@ -247,8 +253,9 @@ static int orion_start(struct watchdog_device *wdt_dev) >>> dev->data->wdt_enable_bit); >>> >>> /* Enable reset on watchdog */ >>> - atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, >>> - dev->data->rstout_enable_bit); >>> + if (!dev->irq) >>> + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, >>> + dev->data->rstout_enable_bit); >>> >>> return 0; >>> } >>> @@ -595,6 +602,8 @@ static int orion_wdt_probe(struct platform_device *pdev) >>> dev_err(&pdev->dev, "failed to request IRQ\n"); >>> goto disable_clk; >>> } >>> + >>> + dev->irq = irq; >>> } >>> >>> watchdog_set_nowayout(&dev->wdt, nowayout); >>> >> >> > > ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured 2019-02-27 20:59 ` Chris Packham @ 2019-02-27 23:07 ` Guenter Roeck 2019-03-04 22:51 ` [PATCH 0/2] watchdog: orion_wdt: add pretimeout support Chris Packham 0 siblings, 1 reply; 19+ messages in thread From: Guenter Roeck @ 2019-02-27 23:07 UTC (permalink / raw) To: Chris Packham Cc: wim, gregory.clement, devicetree, linux-watchdog, linux-kernel On Wed, Feb 27, 2019 at 08:59:07PM +0000, Chris Packham wrote: > Hijacking an old thread, > > On 11/10/17 5:30 PM, Chris Packham wrote: > > On 11/10/17 16:42, Guenter Roeck wrote: > >> On 10/10/2017 07:29 PM, Chris Packham wrote: > >>> The orion_wdt_irq invokes panic() so we are going to reset the CPU > >>> regardless. By not setting this bit we get a chance to gather debug > >>> from the panic output before the system is reset. > >>> > >>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > >> > >> Unless I am missing something, this assumes that the interrupt is > >> handled, ie that the system is not stuck with interrupts disabled. > >> This makes the watchdog less reliable. This added verbosity comes > >> at a significant cost. I'd like to get input from others if this > >> is acceptable. > >> > >> That would be different if there was a means to configure a pretimeout, > >> ie a means to tell the system to generate an irq first, followed by a > >> hard reset if the interrupt is not served. that does not seem to be > >> the case here, though. > >> > > > > As far as I can tell there is no pretimeout capability in the orion > > /armada WDT. I have got a work-in-progress patch that enables the RSTOUT > > in the interrupt handler which some-what mitigates your concern but > > still requires the interrupt to be handled at least once. > > > > Another option would be to use one of the spare global timers to provide > > the interrupt-driven aspect. > > So as Guenter rightly pointed out my original patch meant that we'd hang > if we got stuck in a loop with interrupts disabled. Shortly after that > that's exactly what happened on my test setup. > > I've now been able to follow-up on the idea of using one of the spare > global timers as a pretimeout indication and it's looking pretty > promising. The patch is below (beware MUA wrapping). I'll submit it > properly but I'm wondering if I should add the timer1 based watchdog as > a separate watchdog device or like I have below roll it into the > existing watchdog device. > Why not use a pretimeout ? Isn't this exactly what you are doing, with a fixed pretimeout of timeout / 2 ? Guenter ^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 0/2] watchdog: orion_wdt: add pretimeout support 2019-02-27 23:07 ` Guenter Roeck @ 2019-03-04 22:51 ` Chris Packham 2019-03-04 22:51 ` [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout Chris Packham 2019-03-04 22:51 ` [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout Chris Packham 0 siblings, 2 replies; 19+ messages in thread From: Chris Packham @ 2019-03-04 22:51 UTC (permalink / raw) To: linux, andrew, gregory.clement, jason Cc: linux-arm-kernel, linux-watchdog, linux-kernel, Chris Packham This is a follow up from https://lore.kernel.org/lkml/20190227230707.GA28635@roeck-us.net/ It appears that the kernel has only ever used timer0 on the orion/kirkwood/armada platforms so timer1 appears to be spare on all of these. Armada-XP and Armada-385 also have timers 2 and 3 which could be used in a similar way if it is deemed that timer1 should be kept for some other purpose. Chris Packham (2): watchdog: orion: remove orion_wdt_set_timeout watchdog: orion_wdt: use timer1 as a pretimeout arch/arm/boot/dts/armada-38x.dtsi | 1 + drivers/watchdog/orion_wdt.c | 66 ++++++++++++++++++------------- 2 files changed, 39 insertions(+), 28 deletions(-) -- 2.21.0 ^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout 2019-03-04 22:51 ` [PATCH 0/2] watchdog: orion_wdt: add pretimeout support Chris Packham @ 2019-03-04 22:51 ` Chris Packham 2019-03-05 17:17 ` Guenter Roeck 2019-03-04 22:51 ` [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout Chris Packham 1 sibling, 1 reply; 19+ messages in thread From: Chris Packham @ 2019-03-04 22:51 UTC (permalink / raw) To: linux, andrew, gregory.clement, jason Cc: linux-arm-kernel, linux-watchdog, linux-kernel, Chris Packham, Wim Van Sebroeck The watchdog core will do the same thing if no set_timeout is supplied so we can safely remove orion_wdt_set_timeout. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- drivers/watchdog/orion_wdt.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index 9db3b09f7568..8b259c712c52 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -349,13 +349,6 @@ static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev) return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate; } -static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev, - unsigned int timeout) -{ - wdt_dev->timeout = timeout; - return 0; -} - static const struct watchdog_info orion_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .identity = "Orion Watchdog", @@ -366,7 +359,6 @@ static const struct watchdog_ops orion_wdt_ops = { .start = orion_wdt_start, .stop = orion_wdt_stop, .ping = orion_wdt_ping, - .set_timeout = orion_wdt_set_timeout, .get_timeleft = orion_wdt_get_timeleft, }; -- 2.21.0 ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout 2019-03-04 22:51 ` [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout Chris Packham @ 2019-03-05 17:17 ` Guenter Roeck 0 siblings, 0 replies; 19+ messages in thread From: Guenter Roeck @ 2019-03-05 17:17 UTC (permalink / raw) To: Chris Packham Cc: andrew, gregory.clement, jason, linux-arm-kernel, linux-watchdog, linux-kernel, Wim Van Sebroeck On Tue, Mar 05, 2019 at 11:51:51AM +1300, Chris Packham wrote: > The watchdog core will do the same thing if no set_timeout > is supplied so we can safely remove orion_wdt_set_timeout. > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/orion_wdt.c | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c > index 9db3b09f7568..8b259c712c52 100644 > --- a/drivers/watchdog/orion_wdt.c > +++ b/drivers/watchdog/orion_wdt.c > @@ -349,13 +349,6 @@ static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev) > return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate; > } > > -static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev, > - unsigned int timeout) > -{ > - wdt_dev->timeout = timeout; > - return 0; > -} > - > static const struct watchdog_info orion_wdt_info = { > .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > .identity = "Orion Watchdog", > @@ -366,7 +359,6 @@ static const struct watchdog_ops orion_wdt_ops = { > .start = orion_wdt_start, > .stop = orion_wdt_stop, > .ping = orion_wdt_ping, > - .set_timeout = orion_wdt_set_timeout, > .get_timeleft = orion_wdt_get_timeleft, > }; > > -- > 2.21.0 > ^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout 2019-03-04 22:51 ` [PATCH 0/2] watchdog: orion_wdt: add pretimeout support Chris Packham 2019-03-04 22:51 ` [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout Chris Packham @ 2019-03-04 22:51 ` Chris Packham 2019-03-05 0:57 ` Andrew Lunn 1 sibling, 1 reply; 19+ messages in thread From: Chris Packham @ 2019-03-04 22:51 UTC (permalink / raw) To: linux, andrew, gregory.clement, jason Cc: linux-arm-kernel, linux-watchdog, linux-kernel, Chris Packham, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Wim Van Sebroeck, devicetree The orion watchdog can either reset the CPU or generate an interrupt. The interrupt would be useful for debugging as it provides panic() output about the watchdog expiry, however if the interrupt is used the watchdog can't reset the CPU in the event of being stuck in a loop with interrupts disabled or if the CPU is prevented from accessing memory (e.g. an unterminated DMA). All of the orion based CPU cores (at least back as far as Kirkwood) have spare timers that aren't currently used by the Linux kernel. We can use timer1 to provide a pre-timeout ahead of the watchdog timer and provide the possibility of gathering debug before the reset triggers. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- arch/arm/boot/dts/armada-38x.dtsi | 1 + drivers/watchdog/orion_wdt.c | 58 ++++++++++++++++++++----------- 2 files changed, 39 insertions(+), 20 deletions(-) diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi index 929459c42760..fd0caa9714f2 100644 --- a/arch/arm/boot/dts/armada-38x.dtsi +++ b/arch/arm/boot/dts/armada-38x.dtsi @@ -376,6 +376,7 @@ reg = <0x20300 0x34>, <0x20704 0x4>, <0x18260 0x4>; clocks = <&coreclk 2>, <&refclk>; clock-names = "nbclk", "fixed"; + interrupts-extended = <&gic GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>; }; cpurst: cpurst@20800 { diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index 8b259c712c52..bf1dc75c2045 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -46,6 +46,10 @@ #define WDT_AXP_FIXED_ENABLE_BIT BIT(10) #define WDT_A370_EXPIRED BIT(31) +#define TIMER1_VAL_OFF 0x001c +#define TIMER1_ENABLE_BIT BIT(2) +#define TIMER1_FIXED_ENABLE_BIT BIT(12) + static bool nowayout = WATCHDOG_NOWAYOUT; static int heartbeat = -1; /* module parameter (seconds) */ @@ -118,6 +122,7 @@ static int armada375_wdt_clock_init(struct platform_device *pdev, struct orion_watchdog *dev) { int ret; + u32 val; dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed"); if (!IS_ERR(dev->clk)) { @@ -127,9 +132,8 @@ static int armada375_wdt_clock_init(struct platform_device *pdev, return ret; } - atomic_io_modify(dev->reg + TIMER_CTRL, - WDT_AXP_FIXED_ENABLE_BIT, - WDT_AXP_FIXED_ENABLE_BIT); + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); dev->clk_rate = clk_get_rate(dev->clk); return 0; @@ -158,6 +162,7 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev, struct orion_watchdog *dev) { int ret; + u32 val; dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed"); if (IS_ERR(dev->clk)) @@ -169,38 +174,46 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev, } /* Enable the fixed watchdog clock input */ - atomic_io_modify(dev->reg + TIMER_CTRL, - WDT_AXP_FIXED_ENABLE_BIT, - WDT_AXP_FIXED_ENABLE_BIT); + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); dev->clk_rate = clk_get_rate(dev->clk); + + return 0; } static int orion_wdt_ping(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + /* Reload watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + dev->data->wdt_counter_offset); + writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout), + dev->reg + TIMER1_VAL_OFF); + return 0; } static int armada375_start(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); - u32 reg; + u32 reg, val; /* Set watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + dev->data->wdt_counter_offset); + if (wdt_dev->pretimeout) + writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout), + dev->reg + TIMER1_VAL_OFF); /* Clear the watchdog expiration bit */ atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0); /* Enable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, - dev->data->wdt_enable_bit); + val = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); /* Enable reset on watchdog */ reg = readl(dev->rstout); @@ -214,7 +227,7 @@ static int armada375_start(struct watchdog_device *wdt_dev) static int armada370_start(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); - u32 reg; + u32 reg, val; /* Set watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, @@ -224,8 +237,8 @@ static int armada370_start(struct watchdog_device *wdt_dev) atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0); /* Enable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, - dev->data->wdt_enable_bit); + val = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); /* Enable reset on watchdog */ reg = readl(dev->rstout); @@ -237,14 +250,15 @@ static int armada370_start(struct watchdog_device *wdt_dev) static int orion_start(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 val; /* Set watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + dev->data->wdt_counter_offset); /* Enable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, - dev->data->wdt_enable_bit); + val = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); /* Enable reset on watchdog */ atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, @@ -264,12 +278,14 @@ static int orion_wdt_start(struct watchdog_device *wdt_dev) static int orion_stop(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 mask; /* Disable reset on watchdog */ atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0); /* Disable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + mask = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, mask, 0); return 0; } @@ -277,7 +293,7 @@ static int orion_stop(struct watchdog_device *wdt_dev) static int armada375_stop(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); - u32 reg; + u32 reg, mask; /* Disable reset on watchdog */ atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, @@ -287,7 +303,8 @@ static int armada375_stop(struct watchdog_device *wdt_dev) writel(reg, dev->rstout); /* Disable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + mask = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, mask, 0); return 0; } @@ -295,7 +312,7 @@ static int armada375_stop(struct watchdog_device *wdt_dev) static int armada370_stop(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); - u32 reg; + u32 reg, mask; /* Disable reset on watchdog */ reg = readl(dev->rstout); @@ -303,7 +320,8 @@ static int armada370_stop(struct watchdog_device *wdt_dev) writel(reg, dev->rstout); /* Disable watchdog timer */ - atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + mask = dev->data->wdt_enable_bit | TIMER1_ENABLE_BIT; + atomic_io_modify(dev->reg + TIMER_CTRL, mask, 0); return 0; } @@ -350,7 +368,7 @@ static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev) } static const struct watchdog_info orion_wdt_info = { - .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT, .identity = "Orion Watchdog", }; -- 2.21.0 ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout 2019-03-04 22:51 ` [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout Chris Packham @ 2019-03-05 0:57 ` Andrew Lunn 2019-03-05 1:26 ` Chris Packham 0 siblings, 1 reply; 19+ messages in thread From: Andrew Lunn @ 2019-03-05 0:57 UTC (permalink / raw) To: Chris Packham Cc: linux, gregory.clement, jason, linux-arm-kernel, linux-watchdog, linux-kernel, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Wim Van Sebroeck, devicetree On Tue, Mar 05, 2019 at 11:51:52AM +1300, Chris Packham wrote: > The orion watchdog can either reset the CPU or generate an interrupt. > The interrupt would be useful for debugging as it provides panic() > output about the watchdog expiry, however if the interrupt is used the > watchdog can't reset the CPU in the event of being stuck in a loop with > interrupts disabled or if the CPU is prevented from accessing memory > (e.g. an unterminated DMA). > > All of the orion based CPU cores (at least back as far as Kirkwood) have > spare timers that aren't currently used by the Linux kernel. We can use > timer1 to provide a pre-timeout ahead of the watchdog timer and provide > the possibility of gathering debug before the reset triggers. Hi Chris I had a quick look at other drivers implementing pre-timeout. They seem to call watchdog_notify_pretimeout(). I don't see that here? What happens when timer1 fires? > @@ -169,38 +174,46 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev, > } > > /* Enable the fixed watchdog clock input */ > - atomic_io_modify(dev->reg + TIMER_CTRL, > - WDT_AXP_FIXED_ENABLE_BIT, > - WDT_AXP_FIXED_ENABLE_BIT); > + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT; > + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); > > dev->clk_rate = clk_get_rate(dev->clk); > + > + One blank line is sufficient, > return 0; > } Andrew ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout 2019-03-05 0:57 ` Andrew Lunn @ 2019-03-05 1:26 ` Chris Packham 2019-03-05 2:09 ` Andrew Lunn 2019-03-05 17:27 ` Guenter Roeck 0 siblings, 2 replies; 19+ messages in thread From: Chris Packham @ 2019-03-05 1:26 UTC (permalink / raw) To: Andrew Lunn Cc: linux, gregory.clement, jason, linux-arm-kernel, linux-watchdog, linux-kernel, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Wim Van Sebroeck, devicetree On 5/03/19 1:57 PM, Andrew Lunn wrote: > On Tue, Mar 05, 2019 at 11:51:52AM +1300, Chris Packham wrote: >> The orion watchdog can either reset the CPU or generate an interrupt. >> The interrupt would be useful for debugging as it provides panic() >> output about the watchdog expiry, however if the interrupt is used the >> watchdog can't reset the CPU in the event of being stuck in a loop with >> interrupts disabled or if the CPU is prevented from accessing memory >> (e.g. an unterminated DMA). >> >> All of the orion based CPU cores (at least back as far as Kirkwood) have >> spare timers that aren't currently used by the Linux kernel. Actually this appears to be incorrect Kirkwood does configure timer1 as a clockevent timer. So I can't just grab timer1 for all platforms. >> We can use >> timer1 to provide a pre-timeout ahead of the watchdog timer and provide >> the possibility of gathering debug before the reset triggers. > > Hi Chris > > I had a quick look at other drivers implementing pre-timeout. They > seem to call watchdog_notify_pretimeout(). I don't see that here? What > happens when timer1 fires? > It invokes the regular orion_wdt_irq(). On Armada-385 prior to this change the irq was not specified because the reset always kicked in so there was no point. For correctness I could make the devicetree binding specify 2 interrupts. One for the regular watchdog interrupt (which would never usually get hit because the reset would kick in) and one for the pretimeout/timer1. >> @@ -169,38 +174,46 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev, >> } >> >> /* Enable the fixed watchdog clock input */ >> - atomic_io_modify(dev->reg + TIMER_CTRL, >> - WDT_AXP_FIXED_ENABLE_BIT, >> - WDT_AXP_FIXED_ENABLE_BIT); >> + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT; >> + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); >> >> dev->clk_rate = clk_get_rate(dev->clk); >> + >> + > > One blank line is sufficient, > > >> return 0; >> } > > Andrew > ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout 2019-03-05 1:26 ` Chris Packham @ 2019-03-05 2:09 ` Andrew Lunn 2019-03-05 17:27 ` Guenter Roeck 1 sibling, 0 replies; 19+ messages in thread From: Andrew Lunn @ 2019-03-05 2:09 UTC (permalink / raw) To: Chris Packham Cc: linux, gregory.clement, jason, linux-arm-kernel, linux-watchdog, linux-kernel, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Wim Van Sebroeck, devicetree > > Hi Chris > > > > I had a quick look at other drivers implementing pre-timeout. They > > seem to call watchdog_notify_pretimeout(). I don't see that here? What > > happens when timer1 fires? > > > > It invokes the regular orion_wdt_irq(). On Armada-385 prior to this > change the irq was not specified because the reset always kicked in so > there was no point. > > For correctness I could make the devicetree binding specify 2 > interrupts. One for the regular watchdog interrupt (which would never > usually get hit because the reset would kick in) and one for the > pretimeout/timer1. Hi Chris If the regular watchdog interrupt would never actually fire because the SoC gets reset, maybe make the IRQ handler call watchdog_notify_pretimeout()? Andrew ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout 2019-03-05 1:26 ` Chris Packham 2019-03-05 2:09 ` Andrew Lunn @ 2019-03-05 17:27 ` Guenter Roeck 1 sibling, 0 replies; 19+ messages in thread From: Guenter Roeck @ 2019-03-05 17:27 UTC (permalink / raw) To: Chris Packham Cc: Andrew Lunn, gregory.clement, jason, linux-arm-kernel, linux-watchdog, linux-kernel, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Wim Van Sebroeck, devicetree On Tue, Mar 05, 2019 at 01:26:08AM +0000, Chris Packham wrote: > On 5/03/19 1:57 PM, Andrew Lunn wrote: > > On Tue, Mar 05, 2019 at 11:51:52AM +1300, Chris Packham wrote: > >> The orion watchdog can either reset the CPU or generate an interrupt. > >> The interrupt would be useful for debugging as it provides panic() > >> output about the watchdog expiry, however if the interrupt is used the > >> watchdog can't reset the CPU in the event of being stuck in a loop with > >> interrupts disabled or if the CPU is prevented from accessing memory > >> (e.g. an unterminated DMA). > >> > >> All of the orion based CPU cores (at least back as far as Kirkwood) have > >> spare timers that aren't currently used by the Linux kernel. > > Actually this appears to be incorrect Kirkwood does configure timer1 as > a clockevent timer. So I can't just grab timer1 for all platforms. > If you can't use it unconditionally, can you specify it (and use it) as clock ? > >> We can use > >> timer1 to provide a pre-timeout ahead of the watchdog timer and provide > >> the possibility of gathering debug before the reset triggers. > > > > Hi Chris > > > > I had a quick look at other drivers implementing pre-timeout. They > > seem to call watchdog_notify_pretimeout(). I don't see that here? What > > happens when timer1 fires? > > > > It invokes the regular orion_wdt_irq(). On Armada-385 prior to this > change the irq was not specified because the reset always kicked in so > there was no point. > I would suggest to update that function to actually call watchdog_notify_pretimeout() if a pretimeout is configured configured. After all, we do want to support the infrastructure, and that includes support for the various pretimeout governors (if enabled). > For correctness I could make the devicetree binding specify 2 > interrupts. One for the regular watchdog interrupt (which would never > usually get hit because the reset would kick in) and one for the > pretimeout/timer1. > Yes, if they are different interrupts and orion_wdt_irq() is only supposed to handle the real timeout. Thanks, Guenter > >> @@ -169,38 +174,46 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev, > >> } > >> > >> /* Enable the fixed watchdog clock input */ > >> - atomic_io_modify(dev->reg + TIMER_CTRL, > >> - WDT_AXP_FIXED_ENABLE_BIT, > >> - WDT_AXP_FIXED_ENABLE_BIT); > >> + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT; > >> + atomic_io_modify(dev->reg + TIMER_CTRL, val, val); > >> > >> dev->clk_rate = clk_get_rate(dev->clk); > >> + > >> + > > > > One blank line is sufficient, > > > > > >> return 0; > >> } > > > > Andrew > > > ^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x 2017-10-11 2:29 [PATCH 0/3] getting more output from orion_wdt Chris Packham 2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham 2017-10-11 2:29 ` [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured Chris Packham @ 2017-10-11 2:29 ` Chris Packham 2017-10-12 14:16 ` Gregory CLEMENT 2 siblings, 1 reply; 19+ messages in thread From: Chris Packham @ 2017-10-11 2:29 UTC (permalink / raw) To: linux, wim, gregory.clement, devicetree, linux-watchdog Cc: linux-kernel, Chris Packham, Jason Cooper, Andrew Lunn, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Russell King, linux-arm-kernel The watchdog timer interrupt is available internally on the Armada-38x SoCs. Connect it so that we can have the orion_wdt_irq generate debug information when a watchdog timeout occurs. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- arch/arm/boot/dts/armada-38x.dtsi | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi index 7ff0811e61db..9ac76c54c9e5 100644 --- a/arch/arm/boot/dts/armada-38x.dtsi +++ b/arch/arm/boot/dts/armada-38x.dtsi @@ -408,6 +408,7 @@ reg = <0x20300 0x34>, <0x20704 0x4>, <0x18260 0x4>; clocks = <&coreclk 2>, <&refclk>; clock-names = "nbclk", "fixed"; + interrupts = <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>; }; cpurst: cpurst@20800 { -- 2.14.2 ^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x 2017-10-11 2:29 ` [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x Chris Packham @ 2017-10-12 14:16 ` Gregory CLEMENT 2017-10-12 20:12 ` Chris Packham 0 siblings, 1 reply; 19+ messages in thread From: Gregory CLEMENT @ 2017-10-12 14:16 UTC (permalink / raw) To: Chris Packham Cc: linux, wim, devicetree, linux-watchdog, linux-kernel, Jason Cooper, Andrew Lunn, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Russell King, linux-arm-kernel Hi Chris, On mer., oct. 11 2017, Chris Packham <chris.packham@alliedtelesis.co.nz> wrote: > The watchdog timer interrupt is available internally on the Armada-38x > SoCs. Connect it so that we can have the orion_wdt_irq generate debug > information when a watchdog timeout occurs. Given the patch 2, when an interrupt is provided by the dt, then the behavior of the watchdog changes. So we can't do it for all the platform. As you propose on your cover letter it is better to set it at board level. So instead of this patch you should update the binding documentation with this new resources. Thanks to this each board developer will be able to decide to use this feature or not. Thanks, Gregory > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > --- > arch/arm/boot/dts/armada-38x.dtsi | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi > index 7ff0811e61db..9ac76c54c9e5 100644 > --- a/arch/arm/boot/dts/armada-38x.dtsi > +++ b/arch/arm/boot/dts/armada-38x.dtsi > @@ -408,6 +408,7 @@ > reg = <0x20300 0x34>, <0x20704 0x4>, <0x18260 0x4>; > clocks = <&coreclk 2>, <&refclk>; > clock-names = "nbclk", "fixed"; > + interrupts = <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>; > }; > > cpurst: cpurst@20800 { > -- > 2.14.2 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x 2017-10-12 14:16 ` Gregory CLEMENT @ 2017-10-12 20:12 ` Chris Packham 0 siblings, 0 replies; 19+ messages in thread From: Chris Packham @ 2017-10-12 20:12 UTC (permalink / raw) To: Gregory CLEMENT Cc: linux, wim, devicetree, linux-watchdog, linux-kernel, Jason Cooper, Andrew Lunn, Sebastian Hesselbarth, Rob Herring, Mark Rutland, Russell King, linux-arm-kernel On 13/10/17 03:17, Gregory CLEMENT wrote: > Hi Chris, > > On mer., oct. 11 2017, Chris Packham <chris.packham@alliedtelesis.co.nz> wrote: > >> The watchdog timer interrupt is available internally on the Armada-38x >> SoCs. Connect it so that we can have the orion_wdt_irq generate debug >> information when a watchdog timeout occurs. > > Given the patch 2, when an interrupt is provided by the dt, then the > behavior of the watchdog changes. So we can't do it for all the > platform. > > As you propose on your cover letter it is better to set it at board > level. > > So instead of this patch you should update the binding documentation > with this new resources. Thanks to this each board developer will be > able to decide to use this feature or not. Agreed. I'll drop this patch in favor of a documentation update in v2. > > Thanks, > > Gregory > >> >> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> >> --- >> arch/arm/boot/dts/armada-38x.dtsi | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi >> index 7ff0811e61db..9ac76c54c9e5 100644 >> --- a/arch/arm/boot/dts/armada-38x.dtsi >> +++ b/arch/arm/boot/dts/armada-38x.dtsi >> @@ -408,6 +408,7 @@ >> reg = <0x20300 0x34>, <0x20704 0x4>, <0x18260 0x4>; >> clocks = <&coreclk 2>, <&refclk>; >> clock-names = "nbclk", "fixed"; >> + interrupts = <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>; >> }; >> >> cpurst: cpurst@20800 { >> -- >> 2.14.2 >> > ^ permalink raw reply [flat|nested] 19+ messages in thread
end of thread, other threads:[~2019-03-05 17:27 UTC | newest] Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2017-10-11 2:29 [PATCH 0/3] getting more output from orion_wdt Chris Packham 2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham 2017-10-11 3:35 ` Guenter Roeck 2017-10-11 2:29 ` [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured Chris Packham 2017-10-11 3:41 ` Guenter Roeck 2017-10-11 4:30 ` Chris Packham 2019-02-27 20:59 ` Chris Packham 2019-02-27 23:07 ` Guenter Roeck 2019-03-04 22:51 ` [PATCH 0/2] watchdog: orion_wdt: add pretimeout support Chris Packham 2019-03-04 22:51 ` [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout Chris Packham 2019-03-05 17:17 ` Guenter Roeck 2019-03-04 22:51 ` [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout Chris Packham 2019-03-05 0:57 ` Andrew Lunn 2019-03-05 1:26 ` Chris Packham 2019-03-05 2:09 ` Andrew Lunn 2019-03-05 17:27 ` Guenter Roeck 2017-10-11 2:29 ` [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x Chris Packham 2017-10-12 14:16 ` Gregory CLEMENT 2017-10-12 20:12 ` Chris Packham
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