Hello Uwe, On 24.07.19 09:07, Uwe Kleine-König wrote:
Hello Oliver, On Tue, Jul 23, 2019 at 10:28:18PM +0200, Oliver Hartkopp wrote:I'm running a TS-119P+ and a TS-219P II Qnap NAS with Debian Buster. Both are now running a linux-image-4.19.0-5-marvell kernel. But since my update from Linux 4.9 (Stretch) to Linux 4.19 (Buster) the hardware clock of both boxes refuse to work. After some digging in kernel sources and re-installing Linux 4.9 on my Buster setup it turns out, that a change in the kernel config causes the problem: 4.19.0-5-marvell -> CONFIG_RTC_DRV_S35390A=m (fails) 4.9.0-4-marvell -> CONFIG_RTC_DRV_S35390A=y (works) See details and solving process at: https://marc.info/?l=linux-arm-kernel&m=156390875629259&w=2 Can you please revert the Kernel config parts for the RTC in a way that the RTC drivers are built into the marvell-arch kernel again instead of building them as modules?They were switched to modules because the kernel image got too big to fit into the flash storage of some machines. I assume when we switch to built-in again the resulting problem is the bigger one.
I don't know which is the bigger problem here.When the rtc driver is built as module it can not be operated with the hwclock tool from the util-linux package due to the missing rtc UIE support.
You finally have no hardware clock on these machines and must wait for ntp to shift time and date (my system always starts in February until ntp fixes the time).
Maybe this problem is only relevant for the S35390A and PCF8563 chip which both lack the UIE support needed by hwclock. Both have only alarm triggers in a minute accuracy according to the driver source code.
So CONFIG_RTC_DRV_S35390A=y and CONFIG_RTC_DRV_PCF8563=y should bring back the hw clocks on these machines.
I assume using hwclock without UIE trigger code will impact the accuracy.
As described in the referenced description the hwclock tool does not work on the machines.I'm not sure yet if this is a problem in hwclock() or the s35390a driver.
In detail it is hwclock together with rtc drivers not supporting UIE trigger with a 1 second resolution.
Best regards, Oliver