On Mon, 25 Jan 2021, Mark Jonas wrote:

Hi,

I also intended to send a cover-letter but it was somehow lost on the
way. Here it is:

On an NXP i.MX6 Solo processor we are running an application which
makes use of real-time threads (SCHED_RR). In combination with a
DA9063 we experienced (rare) random shut-downs and reboots. We found
that the issue was caused by a combination of the (default) DA9063
SMBus mode and non-atomic I2C transactions of the i.MX6 I2C driver.
Because a transaction could be idle for longer than the SMBus clock
time-out due to a real-time thread the DA9063 would time-out and
receive the second half of the transaction as an unintended message.

The solution we are giving to review in this patch is to allow using
the I2C mode of the DA9063. We kindly ask for feedback and eventually
hope for an integration to the mainline.

Because we are on a vendor kernel we were not able to test this patch
on the current mainline kernel. Though, we tested a (very similar)
patch on our (close to mainline) Linux 4.14 and 5.4 vendor kernels.

This is the 3rd cover-letter I've received now! :)

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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