Re: [PATCH RFC 4/6] ARM: dts: msm8974: add display support

[Bjorn Andersson]

On Wed 08 May 19:25 PDT 2019, Rob Clark wrote:

> On Wed, May 8, 2019 at 7:16 PM Brian Masney <masneyb@xxxxxxxxxxxxx> wrote:
> >
> > On Mon, May 06, 2019 at 11:39:02PM -0700, Bjorn Andersson wrote:
> > > On Sun 05 May 06:04 PDT 2019, Brian Masney wrote:
> > > > diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi
> > > [..]
> > > > +                           clocks = <&mmcc MDSS_MDP_CLK>,
> > > > +                                    <&mmcc MDSS_AHB_CLK>,
> > > > +                                    <&mmcc MDSS_AXI_CLK>,
> > > > +                                    <&mmcc MDSS_BYTE0_CLK>,
> > > > +                                    <&mmcc MDSS_PCLK0_CLK>,
> > > > +                                    <&mmcc MDSS_ESC0_CLK>,
> > > > +                                    <&mmcc MMSS_MISC_AHB_CLK>;
> > > > +                           clock-names = "mdp_core",
> > > > +                                         "iface",
> > > > +                                         "bus",
> > > > +                                         "byte",
> > > > +                                         "pixel",
> > > > +                                         "core",
> > > > +                                         "core_mmss";
> > >
> > > Unless I enable MMSS_MMSSNOC_AXI_CLK and MMSS_S0_AXI_CLK I get some
> > > underrun error from DSI. You don't see anything like this?
> > >
> > > (These clocks are controlled by msm_bus downstream and should be driven
> > > by interconnect upstream)
> > >
> > >
> > > Apart from this, I think this looks nice. Happy to see the progress.
> >
> > No, I'm not seeing an underrun errors from the DSI. I think the clocks
> > are fine since I'm able to get this working with 4.17 using these same
> > clocks. I just sent out v2 and the cover letter has some details, along
> > with the full dmesg.
> 
> since we don't have interconnect driver for 8974, I guess there is
> some chance that things work or not based on how lk leaves things?
> 

Right, I guess the bootloader on my device does not leave the busses
ticking - perhaps there's a boot splash involved on Brian's device?

Regardless, this works on Nexus 5 and allows Brian to make further
progress so I'm all for merging it.

Regards,
Bjorn