Re: [PATCH v3] gpio: mt7621: fix interrupt banks mapping on gpio chips

[Bartosz Golaszewski]

On Tue, 9 Jun 2026 05:11:18 +0200, Sergio Paracuellos
<sergio.paracuellos@xxxxxxxxx> said:
> The GPIO controller's registers are organized as sets of eight 32-bit
> registers with each set controlling a bank of up to 32 pins. A single
> interrupt is shared for all of the banks handled by the controller.
> The driver implements this using three gpio chip instances every one
> with its own irq chip. Every single pin can generate interrupts having
> a total of 96 possible interrupts here. It looks like there is a problem
> with interrupts being properly mapped to the gpio bank using this solution.
> This problem report is in the following lore's link [0].
>
> Device tree is using two cells for this, so only the interrupt pin and the
> interrupt type are described there. Changing to have three cells to setup
> also the bank and implement 'of_node_instance_match()' would also work but
> this would be an ABI breakage and also a bit incoherent since gpios itself
> are also using two cells and properly mapped in desired bank using through
> its pin number on 'of_xlate()'.
>
> That said, register a linear IRQ domain of the total of 96 interrupts shared
> with the three gpio chip instances so the bank and the interrupt is properly
> decoded and devices using gpio IRQs properly work.
>
> [0]: https://lore.kernel.org/linux-gpio/CAAMcf8C_A9dJ_v4QRKtb9eGNOpJ7BZNOGsFP4i2WFOZxOVBPnQ@xxxxxxxxxxxxxx/T/#u
>
> Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
> Co-developed-by: Vicente Bergas <vicencb@xxxxxxxxx>
> Signed-off-by: Vicente Bergas <vicencb@xxxxxxxxx>
> Tested-by: Vicente Bergas <vicencb@xxxxxxxxx>
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
> ---

This looks relatively good to me. Sashiko points out several issues in remove
path but they're not different from what many other drivers suffer from so I'm
willing to let it slip with the potential of fixing it treewide later.

I won't be sending it for v7.1, it's way too big for rc7. I'll queue it directly
for v7.2 and send it next week with my merge window PR.

Bart