[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 at renesas.com>
>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
>>>
>>> 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 at renesas.com>
> 
> 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 at renesas.com>
>   Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
>   Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> 
> 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!