Re: [PATCH REGRESSION FIX] dw_dmac: make driver's endianness configurable

Andrew Morton
2012-10-23T23:12:31Z

On Sun, 14 Oct 2012 15:54:13 +0800
Hein Tibosch <hein_tibosch@yahoo.es> wrote:

> The dw_dmac was originally developed for avr32 to be used with the Synopsys
> DesignWare AHB DMA controller. Starting from 2.6.38, access to the device's i/o
> memory was done with the little-endian readl/writel functions(1)
>
> This broke the driver for the avr32 platform, because it needs big (native)
> endian accessors.
> This patch makes the endianness configurable using 'DW_DMAC_BIG_ENDIAN_IO',
> which will default be true for AVR32

Do we think this bug should be fixed in earlier kernel versions?

If so, the patch might need to be tweaked for 3.6 and earlier, which
don't have the dma_read_byaddr() definition.