Commit 2cbe7feb authored Nov 08, 2012 by Bartlomiej Zolnierkiewicz Committed by Vinod Koul Jan 07, 2013

dmaengine: add cpu_relax() to busy-loop in dma_sync_wait()

Removal of the busy-loop from dma_sync_wait() is not a trivial
task so just add cpu_relax() to the loop for now.

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dan Williams <djbw@fb.com>

parent e239345f

drivers/dma/dmaengine.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -267,7 +267,10 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
		pr_err("%s: timeout!\n", __func__);
		return DMA_ERROR;
		}
		} while (status == DMA_IN_PROGRESS);
		if (status != DMA_IN_PROGRESS)
		break;
		cpu_relax();
		} while (1);

		return status;
		}