Re: [PATCH 1/1] mfd: da9063: Support SMBus and I2C mode

[Lee Jones]

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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