On Tue, Feb 11, 2025 at 01:03:52PM -0500, Alyssa Rosenzweig wrote: > From: Janne Grunau <j@xxxxxxxxxx> > > The iommu on Apple's M1 and M2 supports only a page size of 16kB and is > mandatory for PCIe devices. Mismatched page sizes will render devices > useless due to non-working DMA. While the iommu prints a warning in this > scenario, it seems a common and hard to debug problem, so prevent it at > build-time. Can we include a sample iommu warning here to help people debug this problem? > Signed-off-by: Janne Grunau <j@xxxxxxxxxx> > Signed-off-by: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx> > --- > drivers/pci/controller/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig > index 9800b768105402d6dd1ba4b134c2ec23da6e4201..507e6ac5d65257578e4eec74b459f6605c9c2907 100644 > --- a/drivers/pci/controller/Kconfig > +++ b/drivers/pci/controller/Kconfig > @@ -39,6 +39,7 @@ config PCIE_APPLE > depends on ARCH_APPLE || COMPILE_TEST > depends on OF > depends on PCI_MSI > + depends on PAGE_SIZE_16KB || COMPILE_TEST > select PCI_HOST_COMMON > help > Say Y here if you want to enable PCIe controller support on Apple > > --- > base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b > change-id: 20250211-pci-16k-4c391a5dcd18 > > Best regards, > -- > Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx> >
