[PATCH 2/2] arm64: dts: qcom: Rename SBC to DragonBoard 410c

On Wed, Oct 4, 2017 at 7:21 PM, Stephen Boyd [off-list ref] wrote:

On 10/04, Rob Clark wrote:

quoted

On Wed, Oct 4, 2017 at 6:09 PM, Stephen Boyd [off-list ref] wrote:

quoted

On 10/04, Rob Clark wrote:

quoted

If we managed to get this in before the 4.14 LTS I might feel
differently.  But afterwards, totally not. :-(

How do you install dtbs onto your device? Should be simple enough
to run 'mv' on the new filename to the old one?

it is part of the kernel package

Are you copying the file out of the arch/arm64/boot/dts
directory? Or you're using dtbs_install rule?

dtbs_install

quoted

but fixing it in the distro means fixing it in *every* distro..

That assumes every distro has a bootloader that's looking for one
file name vs. the other. And that the distro hasn't updated the
bootloader to pick a different name.

well, the distro starts at grub.. u-boot (implementing the uefi
interface, and loading the dtb) is part of the board's "bios".. we
kinda want to avoid having to provide different versions of "bios" for
users to flash depending on kernel version

quoted

if we are going for a workaround, then it should be the kernel
installing a symlink.  Not every distro having to fix things up in the
same way for one particular board.

There was a discussion about this years ago when the dtbs_install
rule was introduced to the kernel makefiles[1]. Maybe the
sentiment has changed, but it seems that people involved in that
thread didn't consider the filename an ABI. Also, take a look at
commit f4d4ffc03efc ("kbuild: dtbs_install: new make target")
where it says:

"Removed option to call external script. Copying the files should
be sufficient and a build system can post-process the install
directory.  Despite the fact an external script is used for
installing the kernel, I don't think that is a pattern that
should be encouraged. I would rather see buildroot type tools
post process the install directory to rename or move dtb files
after installing to a staging directory."

So there is kernel-install (which regen's initrd and runs
/lib/kernel/install.d/* scripts).. but so far afaik it hasn't had to
do board specific fixups.. and since this is a change there would have
to propagate into every distro, I'd prefer either not needing to do
this in the first place, or doing it in dtbs_install..

Then again, for db410c, since prior to 4.14 we didn't have an iommu
driver (which display and gpu needed to work without hacks, and
therefore less interesting for distro users), if we manage to sneak
this change into 4.14, then I guess we could live with the short term
headache of telling distro users to flash a different "bios" depending
on kernel version.

After that, we *really* don't want the headache of handholding users
thru bios upgrade for 4.14-lts to newer kernel upgrade.

BR,
-R

which makes it look like the distro installation scripts would
rename things if desired.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/210562.html

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