The current driver implementation for the DMA tranfers first invalidates the cache for Rx buffers and then cleans the cache for Tx buffers before starting the DMA transfers.
The SPIDEV framework assigns a single buffer for both reception and transmission of data.So the above sequence of invalidating the cache and then cleaning it does not work well when the same buffer is used for Rx & Tx. This patch alters the sequence, i.e first flushes the cache and then invalidate them to ensure data integrity. Signed-off-by: Deepak Sikri <[email protected]> --- drivers/spi/spi-pl022.c | 22 +++++++++++----------- 1 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 1e33b83..2c231b7 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -755,10 +755,10 @@ static void *next_transfer(struct pl022 *pl022) static void unmap_free_dma_scatter(struct pl022 *pl022) { /* Unmap and free the SG tables */ - dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl, - pl022->sgt_tx.nents, DMA_TO_DEVICE); dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl, pl022->sgt_rx.nents, DMA_FROM_DEVICE); + dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); sg_free_table(&pl022->sgt_rx); sg_free_table(&pl022->sgt_tx); } @@ -1009,16 +1009,16 @@ static int configure_dma(struct pl022 *pl022) pl022->cur_transfer->len, &pl022->sgt_tx); /* Map DMA buffers */ - rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl, - pl022->sgt_rx.nents, DMA_FROM_DEVICE); - if (!rx_sglen) - goto err_rx_sgmap; - tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl, pl022->sgt_tx.nents, DMA_TO_DEVICE); if (!tx_sglen) goto err_tx_sgmap; + rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); + if (!rx_sglen) + goto err_rx_sgmap; + /* Send both scatterlists */ rxdesc = dmaengine_prep_slave_sg(rxchan, pl022->sgt_rx.sgl, @@ -1053,12 +1053,12 @@ err_txdesc: dmaengine_terminate_all(txchan); err_rxdesc: dmaengine_terminate_all(rxchan); - dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl, + dma_unmap_sg(txchan->device->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); +err_rx_sgmap: + dma_unmap_sg(rxchan->device->dev, pl022->sgt_tx.sgl, pl022->sgt_tx.nents, DMA_TO_DEVICE); err_tx_sgmap: - dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl, - pl022->sgt_tx.nents, DMA_FROM_DEVICE); -err_rx_sgmap: sg_free_table(&pl022->sgt_tx); err_alloc_tx_sg: sg_free_table(&pl022->sgt_rx); -- 1.7.2.2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
