Messages in this thread | | | Subject | Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure() | From | Robin Murphy <> | Date | Wed, 18 Nov 2015 12:00:32 +0000 |
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+Arnd
On 17/11/15 15:00, Robin Murphy wrote: > Hi Suravee, > > On 28/10/15 22:50, Suravee Suthikulpanit wrote: >> This patch move of_pci_dma_configure() to a more generic >> pci_dma_configure(), which can be extended by non-OF code (e.g. ACPI). >> >> This has no functional change. > > Unfortunately, it appears that it does... > >> 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 :(
Robin.
[1]:https://git.kernel.org/cgit/linux/kernel/git/arm64/linux.git/commit/?h=fixes/core&id=1dccb598df549d892b6450c261da54cdd7af44b4
> Should this be checking bridge->parent->of_node rather than > dev->dev.of_node (which seems to work), or am I missing something? > > Sorry I don't really have the bandwidth to look into this in detail > myself, right now I'm just trying to get my magic hacks rebased ;) > > Robin. > >> + if (bridge->parent) >> + of_dma_configure(&dev->dev, bridge->parent->of_node); >> + } >> + >> + pci_put_host_bridge_device(bridge); >> +}
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