diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_omap.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 65 |
1 files changed, 49 insertions, 16 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index dce1a23706e8..978204333c94 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -98,6 +98,7 @@ struct omap8250_priv { struct pm_qos_request pm_qos_request; struct work_struct qos_work; struct uart_8250_dma omap8250_dma; + spinlock_t rx_dma_lock; }; static u32 uart_read(struct uart_8250_port *up, u32 reg) @@ -726,14 +727,21 @@ static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir); static void __dma_rx_do_complete(struct uart_8250_port *p, bool error) { + struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; struct tty_port *tty_port = &p->port.state->port; struct dma_tx_state state; int count; + unsigned long flags; dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr, dma->rx_size, DMA_FROM_DEVICE); + spin_lock_irqsave(&priv->rx_dma_lock, flags); + + if (!dma->rx_running) + goto unlock; + dma->rx_running = 0; dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); dmaengine_terminate_all(dma->rxchan); @@ -742,6 +750,9 @@ static void __dma_rx_do_complete(struct uart_8250_port *p, bool error) tty_insert_flip_string(tty_port, dma->rx_buf, count); p->port.icount.rx += count; +unlock: + spin_unlock_irqrestore(&priv->rx_dma_lock, flags); + if (!error) omap_8250_rx_dma(p, 0); @@ -753,28 +764,45 @@ static void __dma_rx_complete(void *param) __dma_rx_do_complete(param, false); } +static void omap_8250_rx_dma_flush(struct uart_8250_port *p) +{ + struct omap8250_priv *priv = p->port.private_data; + struct uart_8250_dma *dma = p->dma; + unsigned long flags; + + spin_lock_irqsave(&priv->rx_dma_lock, flags); + + if (!dma->rx_running) { + spin_unlock_irqrestore(&priv->rx_dma_lock, flags); + return; + } + + dmaengine_pause(dma->rxchan); + + spin_unlock_irqrestore(&priv->rx_dma_lock, flags); + + __dma_rx_do_complete(p, true); +} + static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir) { + struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; + int err = 0; struct dma_async_tx_descriptor *desc; + unsigned long flags; switch (iir & 0x3f) { case UART_IIR_RLSI: /* 8250_core handles errors and break interrupts */ - if (dma->rx_running) { - dmaengine_pause(dma->rxchan); - __dma_rx_do_complete(p, true); - } + omap_8250_rx_dma_flush(p); return -EIO; case UART_IIR_RX_TIMEOUT: /* * If RCVR FIFO trigger level was not reached, complete the * transfer and let 8250_core copy the remaining data. */ - if (dma->rx_running) { - dmaengine_pause(dma->rxchan); - __dma_rx_do_complete(p, true); - } + omap_8250_rx_dma_flush(p); return -ETIMEDOUT; case UART_IIR_RDI: /* @@ -786,24 +814,25 @@ static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir) * the DMA won't do anything soon so we have to cancel the DMA * transfer and purge the FIFO manually. */ - if (dma->rx_running) { - dmaengine_pause(dma->rxchan); - __dma_rx_do_complete(p, true); - } + omap_8250_rx_dma_flush(p); return -ETIMEDOUT; default: break; } + spin_lock_irqsave(&priv->rx_dma_lock, flags); + if (dma->rx_running) - return 0; + goto out; desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc) - return -EBUSY; + if (!desc) { + err = -EBUSY; + goto out; + } dma->rx_running = 1; desc->callback = __dma_rx_complete; @@ -815,7 +844,9 @@ static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir) dma->rx_size, DMA_FROM_DEVICE); dma_async_issue_pending(dma->rxchan); - return 0; +out: + spin_unlock_irqrestore(&priv->rx_dma_lock, flags); + return err; } static int omap_8250_tx_dma(struct uart_8250_port *p); @@ -1129,6 +1160,8 @@ static int omap8250_probe(struct platform_device *pdev) priv->latency); INIT_WORK(&priv->qos_work, omap8250_uart_qos_work); + spin_lock_init(&priv->rx_dma_lock); + device_init_wakeup(&pdev->dev, true); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, -1); |