diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/ep93xx_dma.c | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c index deb009c3121f..ec240592f5c8 100644 --- a/drivers/dma/ep93xx_dma.c +++ b/drivers/dma/ep93xx_dma.c @@ -201,6 +201,7 @@ struct ep93xx_dma_engine { struct dma_device dma_dev; bool m2m; int (*hw_setup)(struct ep93xx_dma_chan *); + void (*hw_synchronize)(struct ep93xx_dma_chan *); void (*hw_shutdown)(struct ep93xx_dma_chan *); void (*hw_submit)(struct ep93xx_dma_chan *); int (*hw_interrupt)(struct ep93xx_dma_chan *); @@ -333,21 +334,27 @@ static inline u32 m2p_channel_state(struct ep93xx_dma_chan *edmac) return (readl(edmac->regs + M2P_STATUS) >> 4) & 0x3; } -static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac) +static void m2p_hw_synchronize(struct ep93xx_dma_chan *edmac) { + unsigned long flags; u32 control; + spin_lock_irqsave(&edmac->lock, flags); control = readl(edmac->regs + M2P_CONTROL); control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT); m2p_set_control(edmac, control); + spin_unlock_irqrestore(&edmac->lock, flags); while (m2p_channel_state(edmac) >= M2P_STATE_ON) - cpu_relax(); + schedule(); +} +static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac) +{ m2p_set_control(edmac, 0); - while (m2p_channel_state(edmac) == M2P_STATE_STALL) - cpu_relax(); + while (m2p_channel_state(edmac) != M2P_STATE_IDLE) + dev_warn(chan2dev(edmac), "M2P: Not yet IDLE\n"); } static void m2p_fill_desc(struct ep93xx_dma_chan *edmac) @@ -1163,6 +1170,26 @@ fail: } /** + * ep93xx_dma_synchronize - Synchronizes the termination of transfers to the + * current context. + * @chan: channel + * + * Synchronizes the DMA channel termination to the current context. When this + * function returns it is guaranteed that all transfers for previously issued + * descriptors have stopped and and it is safe to free the memory associated + * with them. Furthermore it is guaranteed that all complete callback functions + * for a previously submitted descriptor have finished running and it is safe to + * free resources accessed from within the complete callbacks. + */ +static void ep93xx_dma_synchronize(struct dma_chan *chan) +{ + struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); + + if (edmac->edma->hw_synchronize) + edmac->edma->hw_synchronize(edmac); +} + +/** * ep93xx_dma_terminate_all - terminate all transactions * @chan: channel * @@ -1325,6 +1352,7 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev) dma_dev->device_prep_slave_sg = ep93xx_dma_prep_slave_sg; dma_dev->device_prep_dma_cyclic = ep93xx_dma_prep_dma_cyclic; dma_dev->device_config = ep93xx_dma_slave_config; + dma_dev->device_synchronize = ep93xx_dma_synchronize; dma_dev->device_terminate_all = ep93xx_dma_terminate_all; dma_dev->device_issue_pending = ep93xx_dma_issue_pending; dma_dev->device_tx_status = ep93xx_dma_tx_status; @@ -1342,6 +1370,7 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev) } else { dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); + edma->hw_synchronize = m2p_hw_synchronize; edma->hw_setup = m2p_hw_setup; edma->hw_shutdown = m2p_hw_shutdown; edma->hw_submit = m2p_hw_submit; |