On Mon, 11 Feb 2019 at 12:23, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > > On 11/02/2019 08:14, Marek Szyprowski wrote: > > Hi Stuart > > > > On 2019-02-10 23:51, Stuart Menefy wrote: > >> When debugging suspend problems on Exynos 5260, I had a large number > >> of debugging prints going to the serial port after interrupts > >> had been disabled but before the timer interrupt was shutdown. This > >> was long enough for a timer tick to occur, but as interrupts were > >> disabled the ISR didn't run, and so the interrupt wasn't cleared. > >> Later when the timer was shutdown the interrupt was left asserted and > >> so the wfi at the heart of the suspend code didn't wait, causing > >> the suspend to fail. > >> > >> Currently the code which stops the timer when it is on one-shot mode > >> and the interrupt occurs is in exynos4_mct_tick_clear(), meaning if we > >> called this from the shutdown code exynos4_mct_tick_stop() could be > >> called twice. So first restructure the existing code, so the check for > >> one-shot mode and stopping the timer is moved to the ISR, leaving > >> exynos4_mct_tick_clear() just clearing the interrupt flag. > >> > >> Once this has been done simply call exynos4_mct_tick_clear() from > >> set_state_shutdown(). > > > > This also fixes mysterious suspend failures on Odroid XU3/XU4/HC1 :) > > > > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > > Applied. Shall I add the stable@ tag? Makes sense - for the second patch, although first is a prerequisite. It should be backported up to v4.3 (the code differ a lot on older versions). Best regards, Krzysztof
