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path: root/drivers/tty/serial/8250
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Diffstat (limited to 'drivers/tty/serial/8250')
-rw-r--r--drivers/tty/serial/8250/8250_dma.c26
-rw-r--r--drivers/tty/serial/8250/8250_em.c4
2 files changed, 25 insertions, 5 deletions
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index bfa1a857f..c8b17070f 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -48,19 +48,39 @@ static void __dma_rx_complete(void *param)
struct uart_8250_dma *dma = p->dma;
struct tty_port *tty_port = &p->port.state->port;
struct dma_tx_state state;
+ enum dma_status dma_status;
int count;
- dma->rx_running = 0;
- dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ /*
+ * New DMA Rx can be started during the completion handler before it
+ * could acquire port's lock and it might still be ongoing. Don't to
+ * anything in such case.
+ */
+ dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ if (dma_status == DMA_IN_PROGRESS)
+ return;
count = dma->rx_size - state.residue;
tty_insert_flip_string(tty_port, dma->rx_buf, count);
p->port.icount.rx += count;
+ dma->rx_running = 0;
tty_flip_buffer_push(tty_port);
}
+static void dma_rx_complete(void *param)
+{
+ struct uart_8250_port *p = param;
+ struct uart_8250_dma *dma = p->dma;
+ unsigned long flags;
+
+ spin_lock_irqsave(&p->port.lock, flags);
+ if (dma->rx_running)
+ __dma_rx_complete(p);
+ spin_unlock_irqrestore(&p->port.lock, flags);
+}
+
int serial8250_tx_dma(struct uart_8250_port *p)
{
struct uart_8250_dma *dma = p->dma;
@@ -126,7 +146,7 @@ int serial8250_rx_dma(struct uart_8250_port *p)
return -EBUSY;
dma->rx_running = 1;
- desc->callback = __dma_rx_complete;
+ desc->callback = dma_rx_complete;
desc->callback_param = p;
dma->rx_cookie = dmaengine_submit(desc);
diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
index 2a76e22d2..5670c8a26 100644
--- a/drivers/tty/serial/8250/8250_em.c
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -102,8 +102,8 @@ static int serial8250_em_probe(struct platform_device *pdev)
memset(&up, 0, sizeof(up));
up.port.mapbase = regs->start;
up.port.irq = irq->start;
- up.port.type = PORT_UNKNOWN;
- up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
+ up.port.type = PORT_16750;
+ up.port.flags = UPF_FIXED_PORT | UPF_IOREMAP | UPF_FIXED_TYPE;
up.port.dev = &pdev->dev;
up.port.private_data = priv;