Hi Geert,
On Tue, Jun 18, 2019 at 11:08 PM Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Magnus,
>
> On Mon, Jun 17, 2019 at 11:16 AM Magnus Damm <magnus.damm@xxxxxxxxx> wrote:
> > From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
> >
> > Update the r8a7740 to use the CMT1 DT compat string documented in:
> > [PATCH 2/8] dt-bindings: timer: renesas, cmt: Update CMT1 on sh73a0 and r8a7740
> >
> > The "renesas,cmt-48" portion is left as-is to avoid breakage until the CMT
> > driver has been updated to make use of the new DT compat strings.
>
> Hence wouldn't it be better to update the driver first, and the DTS in
> the next release, so you can remove the "renesas,cmt-48" portion with
> the single DTS update?
Changing the DTS once sounds nice indeed. I guess my current series
are optimized for easy merge of DT Binding docs and DTS. The driver
changes are considered slow path.
Regarding the driver itself, I was under the impression that
introducing new DT compat strings is often disconnected from removing
old DT compat strings. Do you agree?
This is how I understand your proposed order:
Step 1:
- Update DT binding document to include new compat strings, remove
deprecated compat strings
- Add new DT compat string matching code to the driver
- Mark old DT compat strings in driver as deprecated
Step 2: (Any time after step 1 is complete)
- Convert DTS to use DT new compat strings
Step 3: (After N releases or years)
- Remove deprecated DT compat string matching code in driver
> This is how it was done for R-Car Gen2:
>
> v4.15 has commit 83c79a6d8d7f4821 ("clocksource/drivers/sh_cmt: Support
> separate R-Car Gen2 CMT0/1"),
> v4.16 has commit bf50e0ab4f5062bb ("ARM: dts: r8a7791: Update CMT compat
> strings").
Looking good!
Thanks for your help!
/ magnus
