On Fri, Oct 20, 2017 at 07:25:20PM -0700, Guenter Roeck wrote: > On 10/20/2017 03:54 PM, Jerry Hoemann wrote: > > Add support for WDIOC_GETPRETIMEOUT ioctl so that user applications > > can determine when the NMI should arrive. > > > > Signed-off-by: Jerry Hoemann <[email protected]> > > --- > > drivers/watchdog/hpwdt.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c > > index 67fbe35..ef54b03 100644 > > --- a/drivers/watchdog/hpwdt.c > > +++ b/drivers/watchdog/hpwdt.c > > @@ -50,6 +50,7 @@ > > static bool nowayout = WATCHDOG_NOWAYOUT; > > static char expect_release; > > static unsigned long hpwdt_is_open; > > +static const int pretimeout = 9; > > static void __iomem *pci_mem_addr; /* the PCI-memory > > address */ > > static unsigned long __iomem *hpwdt_timer_reg; > > @@ -622,6 +623,12 @@ static long hpwdt_ioctl(struct file *file, unsigned > > int cmd, > > } > > break; > > + case WDIOC_GETPRETIMEOUT: > > + ret = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); > > + if (ret) > > + ret = -EFAULT; > > + break; > > + > > case WDIOC_SETTIMEOUT: > > ret = get_user(new_margin, p); > > if (ret) > > > > Can you please convert the driver to use the watchdog subsystem instead ? > If there are still improvements needed afterwards, they can still be > implemented, but we really should not make improvements which are > already supported by the watchdog core.
I will look into converting the driver, but would like to get this fix in independently. SuSE brought https://bugzilla.novell.com/show_bug.cgi?id=1042933 to my attention earlier this summer. The submitter was trying to develop a watchdog test where the ping rate was set to be the Timeout/2. The test worked fine until (Timeout/2) < PreTimeout. At this point an NMI would be delivered to the system before the test could refresh the timer. I came to the view that a watchdog that implements a pre-timeout NMI where the value of the pre-timeout is not known programmatically as having a defect. This problem has been around a long time and we could live with it, but figured while I was in fixing other problems, I'd fix this one as well. Thanks -- ----------------------------------------------------------------------------- Jerry Hoemann Software Engineer Hewlett Packard Enterprise -----------------------------------------------------------------------------
