spi: davinci: do not use DMA for vmalloc'ed buffers

Using vmalloc'ed buffers will fail since daVinci has
VIVT cache and only the kernel lowmem virtual address
is invalidated/flushed when performing DMA.
The virtual address returned from vmalloc() is not
invalidated/flushed and may contain stale data when
returning from spi_sync().
Fixes errors when running UBIFS over SPI NOR.
Revert this when all upper layer users of vmalloc'ed
buffers sent to SPI handles cache flushing/invalidating.

Signed-off-by: Frode Isaksen <fisaksen@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Frode Isaksen 2017-02-23 19:02:00 +01:00 committed by Mark Brown
parent 0718b76488
commit 4dd9becbce

View file

@ -482,7 +482,9 @@ static bool davinci_spi_can_dma(struct spi_master *master,
if (spicfg)
can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) &&
(xfer->len >= DMA_MIN_BYTES);
(xfer->len >= DMA_MIN_BYTES) &&
!is_vmalloc_addr(xfer->rx_buf) &&
!is_vmalloc_addr(xfer->tx_buf);
return can_dma;
}