Adding upstream version 4.19.282.upstream/4.19.282

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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;