Messages in this thread | | | Date | Thu, 18 Jan 2018 12:28:26 +0100 | From | Takashi Iwai <> | Subject | Re: Missing watchdog after ACPI watchdog creation failure |
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On Thu, 18 Jan 2018 12:26:37 +0100, Mika Westerberg wrote: > > On Thu, Jan 18, 2018 at 12:20:32PM +0200, Mika Westerberg wrote: > > On Wed, Jan 17, 2018 at 12:53:41PM +0100, Takashi Iwai wrote: > > > Unfortunately we couldn't get approval yet, since it's a prototype > > > machine. > > > > In that case, I think the system itself and its ACPI tables should be > > fixed if possible. Windows relies on that table as well so unless there > > is something terribly wrong in how we allocate resources in Linux, > > Windows should fail the same way. There is good reason why the WDAT > > table is there in the first place so using iTCO to poke the hardware > > directly might cause some other problems. Windows does not have iTCO > > driver at all. > > > > > Meanwhile, the reporter tested the patch below and confirmed to work. > > > (It might be racy for acpi_has_watchdog() call during the probe, but > > > you see the idea.) > > > > I would rather not to add any kinds of quirks for systems that are still > > in development phase and the BIOS can be fixed. Basic idea is that if > > the WDAT table is there we expect it to be correct and at least the > > systems I'm aware of that's the case. > > > > Of course if it turns out to be a problem in a real production system we > > need to find out what the actual problem is (i.e why the resource > > allocation fails in the first place) and fix it there. > > > > That said, if Rafael says we should still add the check, I'll make a > > patch that does it (based on yours) and send it upstream :) > > However, we can still check if the WDAT is actually enabled and prevent > creation of the device in that case. It may be that the BIOS always > exposes the table but the device itself is disabled. > > Can you ask the reporter to try the below patch and see if it helps?
OK, will provide a test kernel and ask for testing with it.
thanks,
Takashi
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