linux-rockchip.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Rob Herring <robh+dt@kernel.org>
To: Johan Jonker <jbx6244@gmail.com>
Cc: devicetree@vger.kernel.org, "heiko@sntech.de" <heiko@sntech.de>,
	Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Linux USB List <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3 6/8] usb: dwc3: of-simple: add compatible for rk3328
Date: Fri, 5 Feb 2021 12:41:45 -0600	[thread overview]
Message-ID: <CAL_JsqJwNdUfoYM8SZmOgMG9iAyZkJ4-kzjjiDDm_mdmghTEOA@mail.gmail.com> (raw)
In-Reply-To: <20210205114011.10381-6-jbx6244@gmail.com>

On Fri, Feb 5, 2021 at 5:40 AM Johan Jonker <jbx6244@gmail.com> wrote:
>
> From: Cameron Nemo <cnemo@tutanota.com>
>
> Add a compatible to be hooked into by the Rockchip rk3328 device tree.
>
> The rk3399 compatible cannot be reused because the rk3328 SoCs may
> require a specialized driver in the future and old device trees must
> remain compatible with newer kernels.

Yes that's important, but...

> Signed-off-by: Cameron Nemo <cnemo@tutanota.com>
> Signed-off-by: Johan Jonker <jbx6244@gmail.com>
> ---
>  drivers/usb/dwc3/dwc3-of-simple.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
> index e62ecd22b..93bc34328 100644
> --- a/drivers/usb/dwc3/dwc3-of-simple.c
> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
> @@ -171,6 +171,7 @@ static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {
>  };
>
>  static const struct of_device_id of_dwc3_simple_match[] = {
> +       { .compatible = "rockchip,rk3328-dwc3" },

Why does this driver need it? In fact, you don't want this driver to
bind to the dwc3 node as we're binding to the 'snps,dwc3' driver.

>         { .compatible = "rockchip,rk3399-dwc3" },

Given the above, you might think we should remove this, but we can't
since there are old dtb's with the dwc3 child node.

Presumably you are getting lucky here (with link order). The kernel
has no logic to decide which driver to bind to if there are 2 matching
drivers. If we did, it would probably be the opposite of what you want
here as we'd pick the most specific match. This driver should probably
bail probe if no dwc3 child node.

Rob

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

  reply	other threads:[~2021-02-05 18:42 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-05 11:40 [PATCH v3 1/8] dt-bindings: usb: convert rockchip,dwc3.txt to yaml Johan Jonker
2021-02-05 11:40 ` [PATCH v3 2/8] arm64: dts: rockchip: optimize clks for rk3399 dwc3 Johan Jonker
2021-02-05 11:40 ` [PATCH v3 3/8] arm64: dts: rockchip: restyle rk3399 usbdrd3_0 node Johan Jonker
2021-02-05 11:40 ` [PATCH v3 4/8] arm64: dts: rockchip: restyle rk3399 usbdrd3_1 node Johan Jonker
2021-02-05 11:40 ` [PATCH v3 5/8] dt-bindings: usb: dwc3: add description for rk3328 Johan Jonker
2021-02-05 11:40 ` [PATCH v3 6/8] usb: dwc3: of-simple: add compatible " Johan Jonker
2021-02-05 18:41   ` Rob Herring [this message]
2021-02-05 11:40 ` [PATCH v3 7/8] arm64: dts: rockchip: add rk3328 dwc3 usb controller node Johan Jonker
2021-02-05 11:40 ` [PATCH v3 8/8] dts64: rockchip: enable dwc3 usb for A95X Z2 Johan Jonker

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAL_JsqJwNdUfoYM8SZmOgMG9iAyZkJ4-kzjjiDDm_mdmghTEOA@mail.gmail.com \
    --to=robh+dt@kernel.org \
    --cc=balbi@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=heiko@sntech.de \
    --cc=jbx6244@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rockchip@lists.infradead.org \
    --cc=linux-usb@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).