Re: [PATCH v2] debugfs: allow to use regmap for print regs

Li Chen
2023-01-23T07:49:41Z

Hi Greg,
---- On Wed, 11 Jan 2023 18:48:38 +0800 Greg Kroah-Hartman wrote ---
> On Wed, Jan 11, 2023 at 04:27:20PM +0800, Li Chen wrote:
> > Hi Greg,
> > ---- On Wed, 11 Jan 2023 15:42:44 +0800 Greg Kroah-Hartman wrote ---
> > > On Wed, Jan 11, 2023 at 03:21:29PM +0800, Li Chen wrote:
> > > > From: Li Chen lchen@ambarella.com>
> > > >
> > > > Currently, debugfs_regset32 only contains void __iomem *base,
> > > > and it is not friendly to regmap user.
> > > >
> > > > Let's add regmap to debugfs_regset32, and add debugfs_print_regmap_reg32
> > > > to allow debugfs_regset32_show handle regmap.
> > > >
> > > > Signed-off-by: Li Chen lchen@ambarella.com>
> > >
> > > Do you have an actual in-kernel user for this new function? We can't
> > > accept new apis without users for obvious reasaons.
> >
> > Actually, both the old debugfs_print_regs32 and the new debugfs_regmap_print_regs32
> > have only one user: debugfs_regset32_show located inside debugfs/file.c.
>
> Yes, but that function is used by lots of drivers in the kernel today,
> which is fine.
>
> > The difference is currently all users(device drivers) only use debugfs_regset32->base,
> > and none of them use debugfs_regset32->regmap, which is provided by this patch.
> >
> > I'm not sure whether it violates the kernel's "no user, no new function" ruler or not.
>
> Yes, you would have to have a user for this functionality for us to be
> able to take the change.
>
> > I use this regmap locally on our SoC driver, but it is still not ready to upstream, really sorry for it,
> > and it is not a good idea to change existing non-regmap users to regmap haha.
> >
> > If you think it does matter, please tell me and I will upload v3 with our SoC driver in the future.
>
> Please add it to your SoC driver patch series instead and I will be glad
> to review it at that point in time. But for now, this shouldn't be
> needed.

This patch is integrated into this series now: http://lists.infradead.org/pipermail/linux-arm-kernel/2023-January/804858.html

and its user is inside the first patch of the series, please help review it, thanks a lot!

Regards,
Li