serial: imx-serial - update RX error counters when DMA is used
Update error counters when DMA is used for receiving data. Do
this by using DMA transaction error event instead error interrupts
to reduce interrupt load.
Tested-by: Peter Senna Tschudin <peter.senna@collabora.com>
Acked-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 1912136..08ccfe1 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -704,6 +704,7 @@
return IRQ_HANDLED;
}
+static void clear_rx_errors(struct imx_port *sport);
static int start_rx_dma(struct imx_port *sport);
/*
* If the RXFIFO is filled with some data, and then we
@@ -729,6 +730,11 @@
temp &= ~(UCR2_ATEN);
writel(temp, sport->port.membase + UCR2);
+ /* disable the rx errors interrupts */
+ temp = readl(sport->port.membase + UCR4);
+ temp &= ~UCR4_OREN;
+ writel(temp, sport->port.membase + UCR4);
+
/* tell the DMA to receive the data. */
start_rx_dma(sport);
}
@@ -961,6 +967,7 @@
if (status == DMA_ERROR) {
dev_err(sport->port.dev, "DMA transaction error.\n");
+ clear_rx_errors(sport);
return;
}
@@ -1057,6 +1064,31 @@
return 0;
}
+static void clear_rx_errors(struct imx_port *sport)
+{
+ unsigned int status_usr1, status_usr2;
+
+ status_usr1 = readl(sport->port.membase + USR1);
+ status_usr2 = readl(sport->port.membase + USR2);
+
+ if (status_usr2 & USR2_BRCD) {
+ sport->port.icount.brk++;
+ writel(USR2_BRCD, sport->port.membase + USR2);
+ } else if (status_usr1 & USR1_FRAMERR) {
+ sport->port.icount.frame++;
+ writel(USR1_FRAMERR, sport->port.membase + USR1);
+ } else if (status_usr1 & USR1_PARITYERR) {
+ sport->port.icount.parity++;
+ writel(USR1_PARITYERR, sport->port.membase + USR1);
+ }
+
+ if (status_usr2 & USR2_ORE) {
+ sport->port.icount.overrun++;
+ writel(USR2_ORE, sport->port.membase + USR2);
+ }
+
+}
+
#define TXTL_DEFAULT 2 /* reset default */
#define RXTL_DEFAULT 1 /* reset default */
#define TXTL_DMA 8 /* DMA burst setting */