From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Wed, 9 Jul 2014 10:26:23 +0000 (+0200)
Subject: spi: sh-msiof: Handle dmaengine_prep_slave_single() failures gracefully
X-Git-Tag: omap-for-v3.17/fixes-against-rc2~157^2^3~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=279d2378c9c4f05bbe41b55625b4003871026266;p=pandora-kernel.git

spi: sh-msiof: Handle dmaengine_prep_slave_single() failures gracefully

As typically a shmobile SoC has less DMA channels than devices that can use
DMA, we may want to prioritize access to the DMA channels in the future.
This means that dmaengine_prep_slave_single() may start failing
arbitrarily.

Handle dmaengine_prep_slave_single() failures gracefully by falling back to
PIO. This requires moving DMA-specific configuration of the MSIOF device
after the call(s) to dmaengine_prep_slave_single().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
---

Reading git-diff-tree failed