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Date: Thu, 2 May 2024 12:25:35 +0300
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Sunil V L <sunilvl@ventanamicro.com>,
	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
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	Albert Ou <aou@eecs.berkeley.edu>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
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	Thomas Gleixner <tglx@linutronix.de>,
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	Haibo1 Xu <haibo1.xu@intel.com>,
	=?iso-8859-1?Q?Bj=F6rn_T=F6pel?= <bjorn@kernel.org>
Subject: Re: [PATCH v5 08/17] ACPI: pci_link: Clear the dependencies after
 probe
Message-ID: <ZjNcDyLRm9c7BAi3@smile.fi.intel.com>
References: <20240501121742.1215792-9-sunilvl@ventanamicro.com>
 <20240501165615.GA758227@bhelgaas>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

On Wed, May 01, 2024 at 11:56:15AM -0500, Bjorn Helgaas wrote:
> On Wed, May 01, 2024 at 05:47:33PM +0530, Sunil V L wrote:
> > RISC-V platforms need to use dependencies between PCI host bridge, Link
> > devices and the interrupt controllers to ensure probe order. The
> > dependency is like below.
> > 
> > Interrupt controller <-- Link Device <-- PCI Host bridge.
> > 
> > If there is no dependency added between Link device and PCI Host Bridge,
> > then the PCI end points can get probed prior to link device, unable to
> > get mapping for INTx.
> > 
> > So, add the link device's HID to dependency honor list and also clear it
> > after its probe.
> > 
> > Since this is required only for architectures like RISC-V, enable this
> > code under a new config option and set this only in RISC-V.

..

> > +	if (IS_ENABLED(CONFIG_ARCH_ACPI_DEFERRED_GSI))
> > +		acpi_dev_clear_dependencies(device);
> 
> This is really a question for Rafael, but it doesn't seem right that
> this completely depends on a config option.

+1 here, fells like a hack and looks like a hack.

> Is there a reason this wouldn't work for all architectures, i.e., what
> would happen if you just called acpi_dev_clear_dependencies()
> unconditionally?

-- 
With Best Regards,
Andy Shevchenko