diff options
| -rw-r--r-- | drivers/dma/tegra20-apb-dma.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index e973cfa69e62..d4c6f131163c 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -24,6 +24,7 @@ #include <linux/pm_runtime.h> #include <linux/reset.h> #include <linux/slab.h> +#include <linux/wait.h> #include "dmaengine.h" @@ -202,6 +203,8 @@ struct tegra_dma_channel { unsigned int slave_id; struct dma_slave_config dma_sconfig; struct tegra_dma_channel_regs channel_reg; + + struct wait_queue_head wq; }; /* tegra_dma: Tegra DMA specific information */ @@ -680,6 +683,7 @@ static irqreturn_t tegra_dma_isr(int irq, void *dev_id) tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status); tdc->isr_handler(tdc, false); tasklet_schedule(&tdc->tasklet); + wake_up_all(&tdc->wq); spin_unlock(&tdc->lock); return IRQ_HANDLED; } @@ -785,6 +789,7 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) tegra_dma_resume(tdc); pm_runtime_put(tdc->tdma->dev); + wake_up_all(&tdc->wq); skip_dma_stop: tegra_dma_abort_all(tdc); @@ -800,10 +805,29 @@ skip_dma_stop: return 0; } +static bool tegra_dma_eoc_interrupt_deasserted(struct tegra_dma_channel *tdc) +{ + unsigned long flags; + u32 status; + + spin_lock_irqsave(&tdc->lock, flags); + status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS); + spin_unlock_irqrestore(&tdc->lock, flags); + + return !(status & TEGRA_APBDMA_STATUS_ISE_EOC); +} + static void tegra_dma_synchronize(struct dma_chan *dc) { struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); + /* + * CPU, which handles interrupt, could be busy in + * uninterruptible state, in this case sibling CPU + * should wait until interrupt is handled. + */ + wait_event(tdc->wq, tegra_dma_eoc_interrupt_deasserted(tdc)); + tasklet_kill(&tdc->tasklet); } @@ -1498,6 +1522,7 @@ static int tegra_dma_probe(struct platform_device *pdev) tasklet_init(&tdc->tasklet, tegra_dma_tasklet, (unsigned long)tdc); spin_lock_init(&tdc->lock); + init_waitqueue_head(&tdc->wq); INIT_LIST_HEAD(&tdc->pending_sg_req); INIT_LIST_HEAD(&tdc->free_sg_req); |