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From: "Arnd Bergmann" <arnd@arndb.de>
To: "Alex Elder" <elder@riscstar.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Cc: daniel@riscstar.com, bhelgaas@google.com,
	linux-kernel@vger.kernel.org, "kernel test robot" <lkp@intel.com>
Subject: Re: [PATCH] misc: Kconfig: tc9564: fix a circular dependency
Date: Fri, 02 Oct 2026 08:02:37 +0200	[thread overview]
Message-ID: <d8890acd-d854-4f66-8ea9-3b30bde41605@app.fastmail.com> (raw)
In-Reply-To: <20261002013306.373689-1-elder@riscstar.com>

On Fri, Oct 2, 2026, at 03:33, Alex Elder wrote:
> The TC9564_PCI config option selects PCI_DYNAMIC_OF_NODES.  But that
> depends on OF_IRQ, and TC9564_PCI does not satisfy that dependency.
>
> Simply adding "depends on OF_IRQ" results in a recursive Kconfig
> dependency.
>
> A little experimentation shows that the recursion can be avoided
> when "depends on OF_IRQ" is added by *depending on* rather than
> *selecting* PCI_QUIRKS.

Hi Alex,

This change looks technically correct, but I find the description
misleading as you are not actually fixing a circular dependency
but instead a missing one.

> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 9c5b1e9d672e8..87ea92af81dca 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -571,9 +571,10 @@ config MCHP_LAN966X_PCI
>  config TC9564_PCI
>  	tristate "Toshiba TC9564 PCI function support"
>  	depends on OF
> +	depends on OF_IRQ
>  	depends on PCI
> +	depends on PCI_QUIRKS
>  	select PCI_DYNAMIC_OF_NODES
> -	select PCI_QUIRKS
>  	default m

I would go further here and simplify this to

config TC9564_PCI
 	tristate "Toshiba TC9564 PCI function support"
        depends on PCI && PCI_DYNAMIC_OF_NODES && PCI_QUIRKS

(in either one or three lines)

CONFIG_PCI_DYNAMIC_OF_NODES is a user-visible option, so you
should not select it from a driver.

  Arnd

  reply	other threads:[~2026-10-02  6:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-02  1:33 Alex Elder
2026-10-02  6:02 ` Arnd Bergmann [this message]
2026-10-02 12:50   ` Alex Elder
2026-10-02 12:55     ` Arnd Bergmann
2026-10-02 14:07       ` Alex Elder

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