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Diffstat (limited to 'drivers/dma/sh')
-rw-r--r--drivers/dma/sh/rcar-dmac.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 2b2c7db3e480..c99fd0f6ff13 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -10,6 +10,7 @@
* published by the Free Software Foundation.
*/
+#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
@@ -741,6 +742,24 @@ static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
/* -----------------------------------------------------------------------------
* Stop and reset
*/
+static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan)
+{
+ u32 chcr;
+ unsigned int i;
+
+ /*
+ * Ensure that the setting of the DE bit is actually 0 after
+ * clearing it.
+ */
+ for (i = 0; i < 1024; i++) {
+ chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
+ if (!(chcr & RCAR_DMACHCR_DE))
+ return;
+ udelay(1);
+ }
+
+ dev_err(chan->chan.device->dev, "CHCR DE check error\n");
+}
static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan)
{
@@ -749,6 +768,7 @@ static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan)
chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE |
RCAR_DMACHCR_TE | RCAR_DMACHCR_DE);
rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr);
+ rcar_dmac_chcr_de_barrier(chan);
}
static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan)
@@ -1481,6 +1501,8 @@ static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev)
if (chcr & RCAR_DMACHCR_TE)
mask |= RCAR_DMACHCR_DE;
rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask);
+ if (mask & RCAR_DMACHCR_DE)
+ rcar_dmac_chcr_de_barrier(chan);
if (chcr & RCAR_DMACHCR_DSE)
ret |= rcar_dmac_isr_desc_stage_end(chan);