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From:   Frank Wunderlich <frank-w@public-files.de>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     Marc Zyngier <maz@kernel.org>, Ryder Lee <ryder.lee@mediatek.com>,
        linux-mediatek@lists.infradead.org,
        Frank Wunderlich <linux@fw-web.de>,
        linux-kernel@vger.kernel.org,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>
Subject: Aw: Re:  Re: [PATCH] pci: mediatek: fix warning in msi.h
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Date:   Wed, 4 Nov 2020 17:49:31 +0100
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> Gesendet: Dienstag, 03. November 2020 um 11:16 Uhr
> Von: "Thomas Gleixner" <tglx@linutronix.de>
> Any architecture which selects PCI_MSI_ARCH_FALLBACKS and does not have
> irqdomain support runs into:
>
> 	if (!d)
> 		bus->bus_flags |=3D PCI_BUS_FLAGS_NO_MSI;
>
> which in turn makes pci_msi_supported() return 0 and consequently makes
> pci_enable_msi[x]() fail.

i'm not that deep into this, but just my thoughts...you are the experts :)

checking for PCI_MSI_ARCH_FALLBACKS here does not help?

something like this:

#ifndef PCI_MSI_ARCH_FALLBACKS
	if (!d)
		bus->bus_flags |=3D PCI_BUS_FLAGS_NO_MSI;
#endif

imho pci_enable_msi[x]() does not do anything if there is no msi-support (=
or does not get called), so maybe check the PCI_BUS_FLAGS_NO_MSI before th=
e call (if this is inside core) or inside the enable-function (if called f=
rom outside)....

or is this the issue marc talkes about (called before flag is set)?

regards Frank