Commit 02ec6041 authored Apr 27, 2015 by John Ogness Committed by Greg Kroah-Hartman May 06, 2015

dmaenegine: edma: allow pause/resume for non-cyclic mode



The 8250_omap serial driver relies on dmaengine_pause() actually
pausing the DMA transfer. Before this patch dmaengine_pause() is
a NOP for non-cylic DMA transfers. This allowed the 8250_omap
driver to read DMA buffers while the DMA was still active,
resulting in lost serial data.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c2d4bb9d

drivers/dma/edma.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -300,8 +300,7 @@ static int edma_dma_pause(struct dma_chan *chan)
		{
		struct edma_chan *echan = to_edma_chan(chan);

		/* Pause/Resume only allowed with cyclic mode */
		if (!echan->edesc \|\| !echan->edesc->cyclic)
		if (!echan->edesc)
		return -EINVAL;

		edma_pause(echan->ch_num);
		@@ -312,10 +311,6 @@ static int edma_dma_resume(struct dma_chan *chan)
		{
		struct edma_chan *echan = to_edma_chan(chan);

		/* Pause/Resume only allowed with cyclic mode */
		if (!echan->edesc->cyclic)
		return -EINVAL;

		edma_resume(echan->ch_num);
		return 0;
		}

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