Re: [PATCH 02/17] clocksource: davinci-timer: new driver

On 17/01/19 7:31 PM, Bartosz Golaszewski wrote:

czw., 17 sty 2019 o 13:42 Sekhar Nori [off-list ref] napisał(a):

quoted

On 16/01/19 2:48 PM, Sekhar Nori wrote:

quoted

On 14/01/19 10:09 PM, Bartosz Golaszewski wrote:

quoted

pon., 14 sty 2019 o 13:20 Sekhar Nori [off-list ref] napisał(a):

quoted

Hi Bartosz,

On 11/01/19 10:51 PM, Bartosz Golaszewski wrote:

quoted

From: Bartosz Golaszewski <redacted>

Currently the clocksource and clockevent support for davinci platforms
lives in mach-davinci. It hard-codes many things, used global variables,
implements functionalities unused by any platform and has code fragments
scattered across many (often unrelated) files.

Implement a new, modern and simplified timer driver and put it into
drivers/clocksource. We still need to support legacy board files so
export a config structure and a function that allows machine code to
register the timer.

We don't check the return values of regmap reads and writes since with
mmio it's only likely to fail due to programmer's errors.

We also don't bother freeing resources on errors in
davinci_timer_register() as the system won't boot without a timer anyway.

Signed-off-by: Bartosz Golaszewski <redacted>

With this series, DA830 fails to boot. Rest of the devices are okay from
boot perspective.

DA830 is pretty unique because it uses the same timer-half for both
clocksource and clockevent. May be you can set the same configuration on
your DA850 to see the same issue? Else, I will enable low-level debug
and try to provide more debug data.

I can't boot da850 with the same config as da830 (0x60 compare
register, compare irq 74) even with the old timer code. Just to make
sure: does da830 boot fine with mainline v5.0-rc2?

Yeah, I did check that without the patch DA830 does boot.

You are right that DA850 lacks compare interrupts for timers 0 and 1.
So, yes, it seems like we will have to shift to timer2 to test
compare interrupts on DA850.

Timers 2 and 3 are a bit different on da850 - for instance they don't
have separate interrupts for bottom and top halfs.

We should only be using the compare feature which has a a separate
interrupt (distinct from top and bottom half interrupts). Only timer 2
and 3 of DA850 have the compare interrupts though. So you will have to
use those timers to be able to test compare feature on DA850.

I configured the old code to use timer 2 - bottom half only with
compare register 0x60 and compare intterupt 74. It boots although very
slowly and something's broken with timekeeping as the clock goes
backwards and forward (seemingly) randomly.

Ah, okay. Timer 2/3 use ASYNC3 as clock input instead of PLL0_AUXCLK.
Did you make adjustment for this too?

Kevin has an OMAP-L137 starter kit - is this the same as da830-evm? If

Yes.

so, then I can get remote access to it and work on this problem.
Otherwise, I can prepare something that works on da850 with broken
timekeeping and let you see if it works correctly on da830.

Alright, happy to test.

Thanks,
Sekhar