Hi Sreekanth ! While looking at some (unrelated) issue where mtp2sas seems to be using 32-bit DMA instead of 64-bit DMA on some POWER platforms, I noticed this patch which was merged as 5fb1bf8aaa832e1e9ca3198de7bbecb8eff7db9c. Can you confirm my understanding that you are: - Setting the DMA mask to 32-bit - Mapping pages for DMA - Changing the DMA mask to 64-bit ? If yes, then I don't think this is a legal thing to do and definitely not something supported by all architectures. It might work by accident, but there is no telling that any translation/DMA mapping provided before a call to set_dma_mask() is still valid after that call. The architecture might have to completely reconfigure the iommu, for example on some PowerPC platforms, we switch from a remapped mapping to a direct linear map of all memory, all translations established before the switch might be lost (it depends on the specific implementation). How does it work on x86 with DMAR ? Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
