On Tue, Dec 2, 2008 at 05:56, Li Yi wrote:
> A drawback about new mmc_spi driver is that, it uses duplex transfer for
> data R/W. On Blackfin SPI only has one DMA channel. Duplex transfer has
> to work in PIO mode, resulting high CPU usage.
>
> So maybe we should keep the old spi_mmc driver, which does not use
> duplex transfer. Or rewrite mmc_spi to not to use duplex transfer at
> all.

or our bus driver should respect is_dma_mapped in the spi_message
structure and the spi_mmc driver should only use a dma buffer on large
buffers rather than small control messages
-mike
_______________________________________________
Linux-kernel-commits mailing list
[email protected]
http://blackfin.uclinux.org/mailman/listinfo/linux-kernel-commits

Reply via email to