On Mon, May 19, 2014 at 09:13:53AM +0100, Thomas Petazzoni wrote: > The Marvell Armada 375 and Armada 38x SOCs, which use the Cortex-A9 > CPU core, the PL310 cache and the Marvell PCIe hardware block are > affected a L2/PCIe deadlock caused by a system erratum when hardware > I/O coherency is used. > > This deadlock can be avoided by mapping the PCIe memory areas as > strongly-ordered (note: MT_UNCACHED is strongly-ordered), and by > removing the outer cache sync done in software. This is implemented in > this patch by: > > * Registering a custom arch_ioremap_caller function that allows to > make sure PCI memory regions are mapped MT_UNCACHED. > > * Adding at runtime the 'arm,io-coherent' property to the PL310 cache > controller. This cannot be done permanently in the DT, because the > hardware I/O coherency can only be enabled when CONFIG_SMP is > enabled, in the current kernel situation. > > Signed-off-by: Thomas Petazzoni <[email protected]>
Acked-by: Catalin Marinas <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
