[PATCH v2 9/9] fsldma: make halt behave nicely on all supported controllers
flat view
STALE5701d
From: Ira W. Snyder <hidden>
Date: 2011-03-02 22:24:32
Also in:
lkml
Subsystem:
dma generic offload engine subsystem, freescale dma driver, the rest · Maintainers:
Vinod Koul, Zhang Wei, Linus Torvalds
Revision v2 of 2 in this series.
Revisions (2)
- v2 current
- v3 [diff vs current]
The original dma_halt() function set the CA (channel abort) bit on both the 83xx and 85xx controllers. This is incorrect on the 83xx, where this bit means TEM (transfer error mask) instead. The 83xx doesn't support channel abort, so we only do this operation on 85xx. Signed-off-by: Ira W. Snyder <redacted> --- drivers/dma/fsldma.c | 19 ++++++++++++++++--- 1 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 40babc1..eb7bc24 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c@@ -216,13 +216,26 @@ static void dma_halt(struct fsldma_chan *chan) u32 mode; int i; + /* read the mode register */ mode = DMA_IN(chan, &chan->regs->mr, 32); - mode |= FSL_DMA_MR_CA; - DMA_OUT(chan, &chan->regs->mr, mode, 32); - mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA); + /* + * The 85xx controller supports channel abort, which will stop + * the current transfer. On 83xx, this bit is the transfer error + * mask bit, which should not be changed. + */ + if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) { + mode |= FSL_DMA_MR_CA; + DMA_OUT(chan, &chan->regs->mr, mode, 32); + + mode &= ~FSL_DMA_MR_CA; + } + + /* stop the DMA controller */ + mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN); DMA_OUT(chan, &chan->regs->mr, mode, 32); + /* wait for the DMA controller to become idle */ for (i = 0; i < 100; i++) { if (dma_is_idle(chan)) return;
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1.7.3.4