spi: dw-mid: avoid potential NULL dereference

When DMA descriptor allocation fails we should not try to assign any fields in
the bad descriptor. The patch adds the necessary checks for that.

Fixes: 7063c0d942 (spi/dw_spi: add DMA support)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Andy Shevchenko 2015-03-02 20:15:58 +02:00 коммит произвёл Mark Brown
Родитель 9d239d353c
Коммит c9dafb27c8
1 изменённых файлов: 6 добавлений и 0 удалений

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@ -139,6 +139,9 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
1,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc)
return NULL;
txdesc->callback = dw_spi_dma_tx_done;
txdesc->callback_param = dws;
@ -184,6 +187,9 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!rxdesc)
return NULL;
rxdesc->callback = dw_spi_dma_rx_done;
rxdesc->callback_param = dws;