R: [PATCH 1/3] watchdog: qcom-wdt: add option to skip pretimeout

ansuelsmth
2020-02-04T16:16:42Z

If something like this is used, msm-timer require interrupts. Without this
configuration, the device is unbootable as the system froze on system
bootup.

timer@200a000 {
compatible = "qcom,kpss-timer", "qcom,msm-timer";
interrupts = <GIC_PPI 1 (GIC_CPU_MASK_SIMPLE(2) |
IRQ_TYPE_EDGE_RISING)>,
<GIC_PPI 2 (GIC_CPU_MASK_SIMPLE(2) |
IRQ_TYPE_EDGE_RISING)>,
<GIC_PPI 3 (GIC_CPU_MASK_SIMPLE(2) |
IRQ_TYPE_EDGE_RISING)>,
<GIC_PPI 4 (GIC_CPU_MASK_SIMPLE(2) |
IRQ_TYPE_EDGE_RISING)>,
<GIC_PPI 5 (GIC_CPU_MASK_SIMPLE(2) |
IRQ_TYPE_EDGE_RISING)>;
no-pretimeout;
reg = <0x0200a000 0x100>;
clock-frequency = <25000000>,
<32768>;
clocks = <&sleep_clk>;
clock-names = "sleep";
cpu-offset = <0x80000>;
};

> On Tue, Feb 04, 2020 at 04:21:01PM +0100, Ansuel Smith wrote:
> > Some platform like ipq806x doesn't support pretimeout.
> > As the driver check if there are available interrupts and ipq806x
> > use msm-timer that require interrupts, the watchdog fail to probe
> > as request_irq tries to use a ppi interrupt. Add an option to skip
> > pretimeout setup and use the normal watchdog probe.
> >
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> > drivers/watchdog/qcom-wdt.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
> > index a494543d3ae1..e689e97e883e 100644
> > --- a/drivers/watchdog/qcom-wdt.c
> > +++ b/drivers/watchdog/qcom-wdt.c
> > @@ -189,6 +189,7 @@ static int qcom_wdt_probe(struct platform_device
> *pdev)
> > u32 percpu_offset;
> > int irq, ret;
> > struct clk *clk;
> > + bool nopretimeout;
> >
> > regs = of_device_get_match_data(dev);
> > if (!regs) {
> > @@ -204,6 +205,8 @@ static int qcom_wdt_probe(struct platform_device
> *pdev)
> > if (!res)
> > return -ENOMEM;
> >
> > + nopretimeout = of_property_read_bool(np, "no-pretimeout");
> > +
> > /* We use CPU0's DGT for the watchdog */
> > if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
> > percpu_offset = 0;
> > @@ -247,7 +250,7 @@ static int qcom_wdt_probe(struct platform_device
> *pdev)
> >
> > /* check if there is pretimeout support */
> > irq = platform_get_irq(pdev, 0);
> > - if (irq > 0) {
> > + if (!nopretimeout && irq > 0) {
>
> That is unnecessary; such platforms should simply not provide an
interrupt.
> Or, in other words, what is the point of assigning an interrupt to be used
> for pretimeout if the platform doesn't support it ? And then to add yet
> another attribute to tell the driver not to use it ?
>
> Guenter
>
> > ret = devm_request_irq(dev, irq, qcom_wdt_isr,
> > IRQF_TRIGGER_RISING,
> > "wdt_bark", &wdt->wdd);
> > --
> > 2.24.0
> >