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Message-ID: <29195ddffa377c5d080552bb5194018681f8f5f7.camel@kernel.crashing.org>
Subject: Re: Multitude of resource assignment functions
From:   Benjamin Herrenschmidt <benh@kernel.crashing.org>
To:     Logan Gunthorpe <logang@deltatee.com>,
        Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Date:   Fri, 28 Jun 2019 06:26:00 +1000
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On Thu, 2019-06-27 at 10:35 -0600, Logan Gunthorpe wrote:
> My worry would be if the firmware depends on any of those PCI resources
> for any of it's calls. For example, laptop firmware often has specific
> code for screen blanking/dimming when the special buttons are pressed.
> If it implements this by communicating with a PCI device then the kernel
> will break things by reassigning all the addresses.
> 
> However, having a kernel parameter to ignore the firmware choices might
> be a good way for us to start testing whether this is a problem or not
> on some systems

As I consolidate that accross archs I can add such a parameter... I
haven't quite folded x86 in yet, but I'm hoping I'll be able to do so
soon. I plan to move some of those x86 specific kernel parameters into
generic code while doing so. I can add this one.

Cheers,
Ben.