[PATCH 4/4] serial: imx-serial - update RX error counters when DMA is used
From: Nandor Han <hidden>
Date: 2016-08-08 14:04:52
Also in:
lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
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 <redacted> Acked-by: Peter Senna Tschudin <redacted> Signed-off-by: Nandor Han <redacted> --- drivers/tty/serial/imx.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
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 @@ out: 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 @@ static void imx_dma_rxint(struct imx_port *sport) 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 @@ static void dma_rx_callback(void *data) if (status == DMA_ERROR) { dev_err(sport->port.dev, "DMA transaction error.\n"); + clear_rx_errors(sport); return; }
@@ -1057,6 +1064,31 @@ static int start_rx_dma(struct imx_port *sport) 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 */
--
2.8.3