Re: [PATCH] PCI: dwc: layerscape: convert to builtin_platform_driver()

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Saravana Kannan <saravanak@google.com>
Cc: Michael Walle <michael@walle.cc>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Roy Zang <roy.zang@nxp.com>, PCI <linux-pci@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Minghuan Lian <minghuan.Lian@nxp.com>,
	Mingkai Hu <mingkai.hu@nxp.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] PCI: dwc: layerscape: convert to builtin_platform_driver()
Date: Thu, 21 Jan 2021 12:01:50 +0100	[thread overview]
Message-ID: <CAMuHMdWvFej-6vkaLM44t7eX2LpkDSXu4_7VH-X-3XRueXTO=A@mail.gmail.com> (raw)
In-Reply-To: <CAGETcx8_6Hp+MWFOhRohXwdWFSfCc7A=zpb5QYNHZE5zv0bDig@mail.gmail.com>

Hi Saravana,

On Thu, Jan 21, 2021 at 1:05 AM Saravana Kannan <saravanak@google.com> wrote:
> On Wed, Jan 20, 2021 at 3:53 PM Michael Walle <michael@walle.cc> wrote:
> > Am 2021-01-20 20:47, schrieb Saravana Kannan:
> > > On Wed, Jan 20, 2021 at 11:28 AM Michael Walle <michael@walle.cc>
> > > wrote:
> > >>
> > >> [RESEND, fat-fingered the buttons of my mail client and converted
> > >> all CCs to BCCs :(]
> > >>
> > >> Am 2021-01-20 20:02, schrieb Saravana Kannan:
> > >> > On Wed, Jan 20, 2021 at 6:24 AM Rob Herring <robh@kernel.org> wrote:
> > >> >>
> > >> >> On Wed, Jan 20, 2021 at 4:53 AM Michael Walle <michael@walle.cc>
> > >> >> wrote:
> > >> >> >
> > >> >> > fw_devlink will defer the probe until all suppliers are ready. We can't
> > >> >> > use builtin_platform_driver_probe() because it doesn't retry after probe
> > >> >> > deferral. Convert it to builtin_platform_driver().
> > >> >>
> > >> >> If builtin_platform_driver_probe() doesn't work with fw_devlink, then
> > >> >> shouldn't it be fixed or removed?
> > >> >
> > >> > I was actually thinking about this too. The problem with fixing
> > >> > builtin_platform_driver_probe() to behave like
> > >> > builtin_platform_driver() is that these probe functions could be
> > >> > marked with __init. But there are also only 20 instances of
> > >> > builtin_platform_driver_probe() in the kernel:
> > >> > $ git grep ^builtin_platform_driver_probe | wc -l
> > >> > 20
> > >> >
> > >> > So it might be easier to just fix them to not use
> > >> > builtin_platform_driver_probe().
> > >> >
> > >> > Michael,
> > >> >
> > >> > Any chance you'd be willing to help me by converting all these to
> > >> > builtin_platform_driver() and delete builtin_platform_driver_probe()?
> > >>
> > >> If it just moving the probe function to the _driver struct and
> > >> remove the __init annotations. I could look into that.
> > >
> > > Yup. That's pretty much it AFAICT.
> > >
> > > builtin_platform_driver_probe() also makes sure the driver doesn't ask
> > > for async probe, etc. But I doubt anyone is actually setting async
> > > flags and still using builtin_platform_driver_probe().
> >
> > Hasn't module_platform_driver_probe() the same problem? And there
> > are ~80 drivers which uses that.
>
> Yeah. The biggest problem with all of these is the __init markers.
> Maybe some familiar with coccinelle can help?

And dropping them will increase memory usage.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds