diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/sh/rcar-dmac.c | 22 |
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); |