On Mittwoch, 22. Dezember 2021 20:39:58 CET Heiko Stübner wrote: > Am Mittwoch, 22. Dezember 2021, 14:52:51 CET schrieb Rob Herring: > > On Wed, Dec 22, 2021 at 6:47 AM Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > > > > > On Tue, Dec 21, 2021 at 10:31:23AM -0400, Rob Herring wrote: > > > > On Mon, Dec 20, 2021 at 12:06:16PM +0100, Sascha Hauer wrote: > > > > > "vpll" is a misnomer. A clock input to a device should be named after > > > > > the usage in the device, not after the clock that drives it. On the > > > > > rk3568 the same clock is driven by the HPLL. > > > > > To fix that, this patch renames the vpll clock to ref clock. > > > > > > > > The problem with this series is it breaks an old kernel with new dt. You > > > > can partially mitigate that with stable kernel backport, but IMO keeping > > > > the old name is not a burden to maintain. > > > > > > As suggested I only removed vpll from the binding document, but not from > > > the code. The code still handles the old binding as well. > > > > The problem is updating rk3399.dtsi. That change won't work with old > > kernels because they won't look for 'ref'. Since you shouldn't change > > it, the binding needs to cover both the old and new cases. > > is "newer dt with old kernel" really a case these days? > > I do understand the new kernel old dt case - for example with the > dtb being provided by firmware. > > But which user would get the idea of updating only the devicetree > while staying with an older kernel? > Side-by-side installations of LTS kernels with new kernels. LTS kernel uses same DT as new kernel because distribution set it up this way. Other scenario: user wants to modify their device tree. They download the latest kernel sources from kernel.org because they can't use over- lays and they don't want to fiddle with decompiled device trees.
