Re: [PATCH 1/6] arm64: dts: qcom: sm8150: add apps_smmu node

From: Nicolas Dechesne
Date: Fri Jun 05 2020 - 10:31:22 EST


On Fri, Jun 5, 2020 at 4:14 PM Sai Prakash Ranjan
<saiprakash.ranjan@xxxxxxxxxxxxxx> wrote:
>
> On 2020-06-05 19:40, Jonathan Marek wrote:
> > On 6/5/20 10:03 AM, Sai Prakash Ranjan wrote:
> >> On 2020-05-29 08:45, Bjorn Andersson wrote:
> >>> On Thu 28 May 20:02 PDT 2020, Jonathan Marek wrote:
> >>>
> >>>>
> >>>>
> >>>> On 5/28/20 10:52 PM, Bjorn Andersson wrote:
> >>>> > On Sat 23 May 19:38 PDT 2020, Jonathan Marek wrote:
> >>>> >
> >>>> > > Add the apps_smmu node for sm8150. Note that adding the iommus field for
> >>>> > > UFS is required because initializing the iommu removes the bypass mapping
> >>>> > > that created by the bootloader.
> >>>> > >
> >>>> >
> >>>> > Unrelated to the patch itself; how do you disable the splash screen on
> >>>> > 8150? "fastboot oem select-display-panel none" doesn't seem to work for
> >>>> > me on the MTP - and hence this would prevent my device from booting.
> >>>> >
> >>>> > Thanks,
> >>>> > Bjorn
> >>>> >
> >>>>
> >>>> I don't have a MTP, but on HDK855, "fastboot oem
> >>>> select-display-panel none"
> >>>> combined with setting the physical switch to HDMI mode (which
> >>>> switches off
> >>>> the 1440x2560 panel) gets it to not setup the display at all (just
> >>>> the
> >>>> fastboot command isn't enough).
> >>>>
> >>>
> >>> Okay, I don't think we have anything equivalent on the MTP, but good
> >>> to
> >>> know.
> >>>
> >>
> >> Actually I tried out this in SM8150 MTP and it works fine for me,
> >>
> >> "fastboot set_active a; fastboot set_active b; fastboot set_active a;
> >> fastboot oem select-display-panel none; fastboot reboot bootloader;
> >> fastboot boot boot-sm8150.img"
> >>
> >> Also I need to switch slots everytime like above, otherwise I always
> >> see some error
> >> while loading the boot image.
> >>
> >
> > What is the error? If it is "FAILED (remote: Failed to
> > load/authenticate boot image: Load Error)" then flashing/erasing
> > boot_a will make it go away ("fastboot erase boot_a") for the next 6
> > or so "failed" boots.
> >
>
> Yes this exact error.

The bootloader maintains a 'boot status' in one of the partition
attributes. After a certain amount of 'failed' boot , it will switch
to the other boot partition. It's the same thing on RB3/DB845c. In our
release for DB845c, we are patching the bootloader so that this
behavior is bypassed. On typical 'product' there is a user space
application that will come and set the partition attribute to indicate
the boot was successful.

For the record, this is the patch we use on 845c:
https://git.linaro.org/landing-teams/working/qualcomm/abl.git/commit/?h=release/LE.UM.2.3.7-09200-sda845.0&id=e3dc60213234ed626161a568ba587ddac63c5158

rebuilding EDK2/ABL requires access to signing tools.. so it might not
be possible for everyone. but in case you can, it should be
straightforward to reuse this patch.

>
>
> -Sai
>
> --
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