On Mon, 9 Jun 2014 11:36:55 +0200 Hans de Goede hdegoede@redhat.com wrote:
The DMA code in sunxi_mmc.c is broken. mmc_trans_data_by_dma() allocates the dma descriptors on the stack, and then exits while the dma transfer is in progress, so the dma engine is reading stack memory which at that point may be re-used. So far we've gotten away with this by luck, but recent u-boot changes have shifted the stack start address by 16 bytes, which combined with dma alignment now exposes this problem.
Since we end up just busy waiting for the dma engine anyway, this commit fixes things by simply removing the dma code, resulting in smaller bug-free code.
Signed-off-by: Hans de Goede hdegoede@redhat.com Acked-by: Ian Campbell ijc@hellion.org.uk
Acked-by: Siarhei Siamashka siarhei.siamashka@gmail.com
Was it a good idea to keep v2014.07 release relying on luck without this patch?