Re: [PATCH 0/3] mtd: spi-nor: fix DMA-unsafe buffer issue between MTD and SPI

On Tue, Dec 26, 2017 at 06:45:28PM +0000, Trent Piepho wrote:

Or, since this only fixes instances of DMA-unsafe buffers used in
access to SPI NOR flash chips, and since there are other SPI master
interface users, those chip specific fixes in some/all spi master
drivers are still needed to fix transfers not originated via spi-nor? 

SPI client drivers are *supposed* to use DMA safe memory already.  How
often that happens in cases where it matters is a separate question, we
definitely have users with smaller transfers that don't do the right
thing but they're normally done using PIO anyway.