Re: [PATCH 1/1] arm64: dts: qcom: Add Lenovo Yoga C630

[Lee Jones]

On Mon, 02 Sep 2019, Bjorn Andersson wrote:

> On Mon 02 Sep 06:24 PDT 2019, Lee Jones wrote:
> 
> > From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > 
> > The Lenovo Yoga C630 is built on the SDM850 from Qualcomm, but this seem
> > to be similar enough to the SDM845 that we can reuse the sdm845.dtsi.
> > 
> > Supported by this patch is: keyboard, battery monitoring, UFS storage,
> > USB host and Bluetooth.
> 
> Applied this to next-20190829 and booted it, got a little bit of EFI FB,
> then the screen goes blank and after a while I'm back in GRUB.
> 
> I've not been able to figure out what's causing this though.

Probably DMA.  There is still an issue in the COM GENI Serial Engine
Driver which reboots the system when a DMA transaction is initiated.

However, with a workaround patch applied to the Serial Engine driver
(drivers/soc/qcom/qcom-geni-se.c) this DTS has no issue booting the
system.

We have ~12 weeks to either fix or elegantly work around the Serial
Engine issue.  IMHO is makes no sense to hold back this enablement
patch (which cannot go in via the -rcs) for something which is likely
to be fixed and applied during v3.4-rcX.

-- 
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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