From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Wed, 18 Nov 2015 13:41:39 +0100
Subject: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to
 pci_dma_configure()
In-Reply-To: <564C6860.4000002@arm.com>
References: <1446072654-5608-1-git-send-email-Suravee.Suthikulpanit@amd.com>
 <564B4111.6010805@arm.com> <564C6860.4000002@arm.com>
Message-ID: <3822315.uJPjk3L2zB@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wednesday 18 November 2015 12:00:32 Robin Murphy wrote:
> On 17/11/15 15:00, Robin Murphy wrote:
> > On 28/10/15 22:50, Suravee Suthikulpanit wrote:
> >> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> >> Acked-by: Rob Herring <robh+dt@kernel.org>
> >> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> >> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> >> CC: Rafael J. Wysocki <rjw@rjwysocki.net>
> [...]
> >> +/**
> >> + * pci_dma_configure - Setup DMA configuration
> >> + * @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 of host bridge's parent (if any).
> >> + */
> >> +static void pci_dma_configure(struct pci_dev *dev)
> >> +{
> >> +    struct device *bridge = pci_get_host_bridge_device(dev);
> >> +
> >> +    if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> >
> > Previously I was seeing of_dma_configure, and thus of_iommu_configure,
> > called for every PCI device on Juno. The check above now prevents this
> > happening, since the PCI devices are probed directly from the bus and
> > don't have OF nodes of their own. They now get left in some
> > half-configured state where arch_setup_dma_ops isn't called either.
> 
> Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now 
> queued[1]) makes this even worse, since preventing arch_setup_dma_ops 
> being called means the PCI devices now get the dummy DMA ops which leave 
> the drivers failing to probe at all, IOMMU hacks or not 

Ok, glad we found that with my patch then. We really have to
configure the DMA (offset/size/coherency/iommu) for all devices that might
be masters, otherwise things can randomly go wrong.

	ARnd