[PATCH V3 1/2] i2c: qup: Fix broken dma when CONFIG_DEBUG_SG is enabled

Wolfram Sang wsa at the-dreams.de
Thu May 26 11:48:05 PDT 2016

> sg_set_buf expects that the buf parameter passed in should be from
> lowmem and a valid pageframe. This is not true for pages from
> dma_alloc_coherent which can be carveouts, hence the check fails.

OK, given you mean dma_pool_alloc here, the check fails for the
pageframe because of the pool? Is my understanding correct?

> Change allocation of sg buffers from dma_coherent memory to kzalloc
> to fix the issue.

But why can you drop the coherency?

> @@ -1268,6 +1260,8 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
>  		}
>  	}
> +	idx = 0;
> +

This looks like an unrelated change.

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