diff options
| -rw-r--r-- | drivers/dma/ep93xx_dma.c | 60 |
1 files changed, 48 insertions, 12 deletions
diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c index 526a7424f6a..59e7a965772 100644 --- a/drivers/dma/ep93xx_dma.c +++ b/drivers/dma/ep93xx_dma.c @@ -246,6 +246,9 @@ static void ep93xx_dma_set_active(struct ep93xx_dma_chan *edmac, static struct ep93xx_dma_desc * ep93xx_dma_get_active(struct ep93xx_dma_chan *edmac) { + if (list_empty(&edmac->active)) + return NULL; + return list_first_entry(&edmac->active, struct ep93xx_dma_desc, node); } @@ -263,16 +266,22 @@ ep93xx_dma_get_active(struct ep93xx_dma_chan *edmac) */ static bool ep93xx_dma_advance_active(struct ep93xx_dma_chan *edmac) { + struct ep93xx_dma_desc *desc; + list_rotate_left(&edmac->active); if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) return true; + desc = ep93xx_dma_get_active(edmac); + if (!desc) + return false; + /* * If txd.cookie is set it means that we are back in the first * descriptor in the chain and hence done with it. */ - return !ep93xx_dma_get_active(edmac)->txd.cookie; + return !desc->txd.cookie; } /* @@ -327,9 +336,15 @@ static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac) static void m2p_fill_desc(struct ep93xx_dma_chan *edmac) { - struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac); + struct ep93xx_dma_desc *desc; u32 bus_addr; + desc = ep93xx_dma_get_active(edmac); + if (!desc) { + dev_warn(chan2dev(edmac), "M2P: empty descriptor list\n"); + return; + } + if (ep93xx_dma_chan_direction(&edmac->chan) == DMA_MEM_TO_DEV) bus_addr = desc->src_addr; else @@ -491,7 +506,13 @@ static void m2m_hw_shutdown(struct ep93xx_dma_chan *edmac) static void m2m_fill_desc(struct ep93xx_dma_chan *edmac) { - struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac); + struct ep93xx_dma_desc *desc; + + desc = ep93xx_dma_get_active(edmac); + if (!desc) { + dev_warn(chan2dev(edmac), "M2M: empty descriptor list\n"); + return; + } if (edmac->buffer == 0) { writel(desc->src_addr, edmac->regs + M2M_SAR_BASE0); @@ -669,24 +690,30 @@ static void ep93xx_dma_tasklet(unsigned long data) { struct ep93xx_dma_chan *edmac = (struct ep93xx_dma_chan *)data; struct ep93xx_dma_desc *desc, *d; - dma_async_tx_callback callback; - void *callback_param; + dma_async_tx_callback callback = NULL; + void *callback_param = NULL; LIST_HEAD(list); spin_lock_irq(&edmac->lock); + /* + * If dma_terminate_all() was called before we get to run, the active + * list has become empty. If that happens we aren't supposed to do + * anything more than call ep93xx_dma_advance_work(). + */ desc = ep93xx_dma_get_active(edmac); - if (desc->complete) { - edmac->last_completed = desc->txd.cookie; - list_splice_init(&edmac->active, &list); + if (desc) { + if (desc->complete) { + edmac->last_completed = desc->txd.cookie; + list_splice_init(&edmac->active, &list); + } + callback = desc->txd.callback; + callback_param = desc->txd.callback_param; } spin_unlock_irq(&edmac->lock); /* Pick up the next descriptor from the queue */ ep93xx_dma_advance_work(edmac); - callback = desc->txd.callback; - callback_param = desc->txd.callback_param; - /* Now we can release all the chained descriptors */ list_for_each_entry_safe(desc, d, &list, node) { /* @@ -706,13 +733,22 @@ static void ep93xx_dma_tasklet(unsigned long data) static irqreturn_t ep93xx_dma_interrupt(int irq, void *dev_id) { struct ep93xx_dma_chan *edmac = dev_id; + struct ep93xx_dma_desc *desc; irqreturn_t ret = IRQ_HANDLED; spin_lock(&edmac->lock); + desc = ep93xx_dma_get_active(edmac); + if (!desc) { + dev_warn(chan2dev(edmac), + "got interrupt while active list is empty\n"); + spin_unlock(&edmac->lock); + return IRQ_NONE; + } + switch (edmac->edma->hw_interrupt(edmac)) { case INTERRUPT_DONE: - ep93xx_dma_get_active(edmac)->complete = true; + desc->complete = true; tasklet_schedule(&edmac->tasklet); break; |