Re: [PATCH AUTOSEL 5.4 2/5] gpio: ixp4xx: Make irqchip immutable

From: Marc Zyngier
Date: Thu Sep 22 2022 - 05:17:41 EST


Hi Bartosz,

On Wed, 21 Sep 2022 21:04:27 +0100,
Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>
> On Wed, Sep 21, 2022 at 6:57 PM Marc Zyngier <maz@xxxxxxxxxx> wrote:
> >
> > On 2022-09-21 16:54, Sasha Levin wrote:
> > > From: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > >
> > > [ Upstream commit 94e9bc73d85aa6ecfe249e985ff57abe0ab35f34 ]
> > >
> > > This turns the IXP4xx GPIO irqchip into an immutable
> > > irqchip, a bit different from the standard template due
> > > to being hierarchical.
> > >
> > > Tested on the IXP4xx which uses drivers/ata/pata_ixp4xx_cf.c
> > > for a rootfs on compact flash with IRQs from this GPIO
> > > block to the CF ATA controller.
> > >
> > > Cc: Marc Zyngier <maz@xxxxxxxxxx>
> > > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > > Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
> > > Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
> > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> >
> > Why? The required dependencies are only in 5,19, and are
> > definitely NOT a stable candidate...
> >
> > This isn't a fix by any stretch of the imagination.
> >
>
> Hi Marc,
>
> While I didn't mark it for stable (and it shouldn't go into any branch
> earlier than 5.19.x), I did send the patches making the irqchips
> immutable to Linus Torvalds as fixes as they technically do *fix* the
> warning emitted by gpiolib and make the implementation correct.
>
> I think these patches should still be part of the v5.19.x stable branch.

5.19, sure. All the dependencies are there, and tightening the driver
implementations is a valuable goal.

However, targeting all the other stable releases (5.4, 5.10, 5.15)
makes little sense. It won't even compile! Do the dependencies need to
be backported? I don't think it is worthwhile, as this is a long
series containing multiple related changes spread all over the tree.
This would defeat the very purpose of a stable tree.

M.

--
Without deviation from the norm, progress is not possible.