Hi,

On 05/30/2014 10:54 AM, Ian Campbell wrote:
> On Thu, 2014-05-29 at 23:51 +0200, Hans de Goede 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.
> 
> Should/couldn't this go to uboot upstream, which has the mmc stuff now? 

Yes, I'm literary minutes away from sending a patch-set upstream which
includes this now. Actually trying to get sun4i / sun5i to work with
the latest upstream u-boot-arm/master code is what made me hit this bug
(and cost me a day to debug).

Regards,

Hans

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