From: Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [V4 PATCH 3/6] pci: Generic function for setting up PCI device
 DMA coherency
Date: Wed, 20 May 2015 10:24:15 +0100
Message-ID: <20150520092415.GA25313@e104818-lin.cambridge.arm.com>
References: <1431724994-21601-1-git-send-email-Suravee.Suthikulpanit@amd.com>
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Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>,
	linaro-acpi@lists.linaro.org, will.deacon@arm.com,
	herbert@gondor.apana.org.au, al.stone@linaro.org,
	linux-acpi@vger.kernel.org, Murali Karicheri <m-karicheri2@ti.com>,
	msalter@redhat.com, grant.likely@linaro.org, hanjun.guo@linaro.org,
	thomas.lendacky@amd.com, arnd@arndb.de,
	Rob Herring <robh+dt@kernel.org>, bhelgaas@google.com,
	linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, leo.duran@amd.com,
	linux-crypto@vger.kernel.org, lenb@kernel.org,
	David Woodhouse <dwmw2@infradead.org>, davem@davemloft.net
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
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On Sat, May 16, 2015 at 01:59:00AM +0200, Rafael J. Wysocki wrote:
> On Friday, May 15, 2015 04:23:11 PM Suravee Suthikulpanit wrote:
> > +/**
> > + * pci_dma_configure - Setup DMA configuration
> > + * @pci_dev: ptr to pci_dev struct of the PCI device
> > + *
> > + * Function to update PCI devices's DMA configuration using the same
> > + * info from the OF node or ACPI node of host bridge's parent (if any).
> > + */
> > +static void pci_dma_configure(struct pci_dev *pci_dev)
> > +{
> > +	struct device *dev = &pci_dev->dev;
> > +	struct device *bridge = pci_get_host_bridge_device(pci_dev);
> > +	struct device *host = bridge->parent;
> > +	struct acpi_device *adev;
> > +
> > +	if (!host)
> > +		return;
> > +
> > +	if (acpi_disabled) {
> > +		of_dma_configure(dev, host->of_node);
> 
> I'd rather do
> 
> 	if (IS_ENABLED(CONFIG_OF) && host->of_node) {
> 		of_dma_configure(dev, host->of_node);

Nitpick: do we need the CONFIG_OF check? If disabled, I don't think
anyone would set host->of_node.

-- 
Catalin