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

From: Mark Brown
Date: Wed Dec 27 2017 - 05:36:50 EST


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.

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