From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: Rob Herring <robh@kernel.org>
Cc: Peter Chen <peter.chen@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>,
Arnd Bergmann <arnd@arndb.de>, Tony Lindgren <tony@atomide.com>
Subject: Re: ChipIdea USB regression
Date: Mon, 17 Jan 2022 09:26:56 +0000 [thread overview]
Message-ID: <20220117092656.GM18506@ediswmail.ad.cirrus.com> (raw)
In-Reply-To: <CAL_JsqKWMLi69kXp0fcdqLD039eSPwi=NPkPpOWKy=va1+YXow@mail.gmail.com>
On Sat, Jan 15, 2022 at 09:55:23AM -0600, Rob Herring wrote:
> On Fri, Jan 14, 2022 at 5:18 AM Charles Keepax
> <ckeepax@opensource.cirrus.com> wrote:
> > On Fri, Jan 14, 2022 at 10:56:20AM +0000, Charles Keepax wrote:
> > So when that patch copies the DT node to the new platform device
> > in ci_hdrc_add_device it copies the compatible stuff as well as
> > the IRQ stuff it was targeting, this presumably causes the kernel
> > to bind a new copy of the driver to that new device, which probes
> > and calls ci_hdrc_add_device again repeating the process until
> > it dies.
> >
> > Kinda looks to me like the best solution might just be to revert
> > the patch, I am not sure I see how that copy of the DT is supposed
> > to work?
>
> It's not copying the DT, but yes AFAICT it does match and bind the
> child device on the parent driver using the compatible match instead
> of matching on driver name. I think we can use the of_reuse_node flag
> to avoid this in the match, but that needs some more investigation.
Assuming you mean the of_node_reused flag, looks like it already
being set, your code does this:
@@ -864,6 +864,7 @@ struct platform_device *ci_hdrc_add_device(struct device *dev,
pdev->dev.parent = dev;
+ device_set_of_node_from_dev(&pdev->dev, dev);
And that function does this:
void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
{
of_node_put(dev->of_node);
dev->of_node = of_node_get(dev2->of_node);
dev->of_node_reused = true;
}
EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
I guess maybe that flag doesn't do what it is supposed to for
some reason?
Thanks,
Charles
next prev parent reply other threads:[~2022-01-17 9:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-14 10:56 ChipIdea USB regression Charles Keepax
2022-01-14 11:18 ` Charles Keepax
2022-01-15 15:55 ` Rob Herring
2022-01-17 9:26 ` Charles Keepax [this message]
2022-01-17 9:55 ` Charles Keepax
2022-01-18 14:39 ` Rob Herring
2022-01-18 16:16 ` Charles Keepax
2022-01-16 10:21 ` Thorsten Leemhuis
2022-01-18 16:53 ` Rob Herring
2022-01-18 17:33 ` Thorsten Leemhuis
2022-01-18 18:37 ` Rob Herring
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