On 05/04/11 16:49, Jonathan Cameron wrote: > On 05/04/11 16:22, Alexander Stein wrote: >> req.sample needs its own cacheline otherwise accessing req.msg fetches >> it in again. >> Put req onto stack as it doesn't need to be DMA save. >> req.sample is kzalloced itself for DMA access. >> req.command doesn't need own cache line because it will only be written to >> memory on dma_map_single. req.scratch is unsed at all. >> >> Note: This effect doesn't occur if the underlying SPI driver doesn't use >> DMA at all. >> > How about using ____cacheline_aligned having moved 'sample' to the end of the > structure? > > e.g. > > ... > struct spi_transfer xfer[6]; > __be16 sample ____cacheline_aligned; > } hmm. I should probably have glanced further up the thread. Michael beat me to it with the same suggestion! -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
