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Date: Tue, 5 Mar 2024 08:24:26 -0600
From: Rob Herring <robh@kernel.org>
To: Vidya Sagar <vidyas@nvidia.com>
Cc: bhelgaas@google.com, rafael@kernel.org, lenb@kernel.org,
	will@kernel.org, lpieralisi@kernel.org, kw@linux.com,
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	treding@nvidia.com, jonathanh@nvidia.com, kthota@nvidia.com,
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Subject: Re: [PATCH V4] PCI: Add support for preserving boot configuration
Message-ID: <20240305142426.GB3259724-robh@kernel.org>
References: <20240222124110.2681455-1-vidyas@nvidia.com>
 <20240223080021.1692996-1-vidyas@nvidia.com>
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In-Reply-To: <20240223080021.1692996-1-vidyas@nvidia.com>

On Fri, Feb 23, 2024 at 01:30:21PM +0530, Vidya Sagar wrote:
> Add support for preserving the boot configuration done by the
> platform firmware per host bridge basis, based on the presence of
> 'linux,pci-probe-only' property in the respective PCI host bridge
> device-tree node. It also unifies the ACPI and DT based boot flows
> in this regard.
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V4:
> * Addressed Bjorn's review comments
> 
> V3:
> * Unified ACPI and DT flows as part of addressing Bjorn's review comments
> 
> V2:
> * Addressed issues reported by kernel test robot <lkp@intel.com>
> 
>  drivers/acpi/pci_root.c                  | 12 -------
>  drivers/pci/controller/pci-host-common.c |  4 ---
>  drivers/pci/of.c                         | 21 +++++++++++
>  drivers/pci/probe.c                      | 46 ++++++++++++++++++------
>  include/linux/of_pci.h                   |  6 ++++
>  5 files changed, 62 insertions(+), 27 deletions(-)

One more thing.

> @@ -3080,20 +3106,18 @@ int pci_host_probe(struct pci_host_bridge *bridge)
>  
>  	bus = bridge->bus;
>  
> +	/* If we must preserve the resource configuration, claim now */
> +	if (pci_has_flag(PCI_PROBE_ONLY) || bridge->preserve_config)
> +		pci_bus_claim_resources(bus);

No reason to check PCI_PROBE_ONLY if you set preserve_config based on 
/chosen as well. IOW, we should deprecate PCI_PROBE_ONLY flag in favor 
of the per host bridge setting.

Rob