Am 15.12.2018 um 08:50 schrieb H. Nikolaus Schaller hns@goldelico.com:
Hi Tony,
Am 13.12.2018 um 19:14 schrieb Tony Lindgren tony@atomide.com:
- H. Nikolaus Schaller hns@goldelico.com [181208 21:35]:
Hi Tony, I had the OMAP5 running very very hot by a kernel hang (most likely a spinlock). And I wondered if there is no safety mechanism (watchdog timer).
I did a little research and there seems to be no WDT driver for the Palmas in mainline.
There was something:
https://lore.kernel.org/patchwork/patch/367777/
but it seems it did not arrive upstream. Any reasons or problems with the driver? Or a newer version sitting in some git?
Sorry no idea. Maybe check if it's similar to the drivers/watchdog/twl4030_wdt.c?
Yes, it is. Code structure is almost the same, because it is based on twl4030 code :)
Differences:
- uses enable/disable instead of start/stop (probably older WDT core API and easy to fix)
- different compatible list (obviously necessary)
- uses palmas_write() from include/linux/mfd/palmas.h instead of twl_i2c_write_u8() from include/linux/mfd/twl.h
- (have not checked): probably different register offsets
- has no remove/suspend/resume handlers (probably older WDT core API and easy to copy&paste)
But there seems to be a bug in palmas_wdt_write(). IMHO it ignores the "data" argument when passing down to palmas_write()...
So it may be that the driver did not work as proposed.
I am not sure but I think I had spotted a v10 of the patch set.
Ah, yes:
https://lore.kernel.org/patchwork/patch/367819/
There are already several review comments (including confirmation of the data argument issue) but I could not find a v11 or v12.
Note that some devices just use drivers/watchdog/omap_wdt.c
I have looked into that as well and to me it appears to support OMAP3 only.
that is wired to the PMIC used. So maybe the Palmas WDT was just forgotten if it was not needed?
Maybe it was simply forgotten to be completed and resubmitted.
I am not sure if Graeme is still actively working on this topic. So I put him on CC.
BR and thanks, Nikolaus
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