Re: [PATCH v2 3/4] irqchip/gic-v3: Add Renesas R-Car Gen4 erratum workaround

[Marek Vasut]

On 6/22/26 8:55 AM, Marc Zyngier wrote:

Hello Marc,

> > On 6/21/26 12:59 PM, Thomas Gleixner wrote:
> > > On Fri, Jun 19 2026 at 00:02, Marek Vasut wrote:
> > > > Renesas R-Car S4/V4H/V4M GIC600 integration has address width for AXI
> > > > or APB interface configured to 32 bit, it can therefore access only
> > > > the first 4 GiB of physical address space. This information comes from
> > > > R-Car V4H Interface Specification sheet, there is currently no technical
> > > > update number assigned to this limitation. Further input from hardware
> > > > engineer indicates that this limitation also applies to R-Car S4 and V4M.
> > > > Name the limitation GEN4GICITS1, and add a driver quirk to mitigate this
> > > > limitation.
> > > >
> > > > The quirk is keyed on the combination of the GIC implementation
> > > > and the platform identification in the device tree.
> > > >
> > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > > > Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> > >
> > > This SOB chain is broken.
> >
> > Broken ? I don't understand , could you please elaborate ?
>
> Either Shimoda-san is the sole author of the change and you are
> posting their work, then the first line of the patch should say:
>
>   From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>
> with your own SoB immediately following their SoB (see [1]).
>
> Or this has been co-developed, and both of you should be credited as
> authors. then Shimoda-san's SoB should be preceded by their
> Co-developed-by: tag (see [2]).
>
>   Co-developed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>   Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>   Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
>
> This shows exactly who did what, who forwarded whose patch, and forms
> the base of the DCO which is documented at [3].
>
> Thanks,
>
> 	M.
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n449
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n503
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n396
Thank you very much for the clarification!