serial: sirf: let uart's receive start in right place

While UART work in DMA mode, function start_rx will request descriptor
from DMA engine, if there is no left descriptor UART, driver will give
err logs "DMA slave single fail".

currently start_rx is called in set_termios function, so everytime, port
setting will call start_rx once.

Now put start_rx in startup, it will be called once while open the port.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 16 insertions, 30 deletions

diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 8cac7ac497e8..c6657de78997 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -413,7 +413,6 @@ sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count)
                         break;
         }
 
-        sirfport->rx_io_count += rx_count;
         port->icount.rx += rx_count;
 
         return rx_count;
@@ -600,7 +599,6 @@ static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
         struct sirfsoc_uart_port *sirfport = to_sirfport(port);
         struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
         struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
-        sirfport->rx_io_count = 0;
         wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
                 rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
                 ~SIRFUART_IO_MODE);
@@ -632,31 +630,6 @@ static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
                                 sirfport->uart_reg->uart_type));
 }
 
-static void sirfsoc_uart_start_rx(struct uart_port *port)
-{
-        struct sirfsoc_uart_port *sirfport = to_sirfport(port);
-        struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
-        struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
-
-        sirfport->rx_io_count = 0;
-        wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
-        wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
-        wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
-        if (sirfport->rx_dma_chan)
-                sirfsoc_uart_start_next_rx_dma(port);
-        else {
-                if (!sirfport->is_atlas7)
-                        wr_regl(port, ureg->sirfsoc_int_en_reg,
-                                rd_regl(port, ureg->sirfsoc_int_en_reg) |
-                                SIRFUART_RX_IO_INT_EN(uint_en,
-                                        sirfport->uart_reg->uart_type));
-                else
-                        wr_regl(port, ureg->sirfsoc_int_en_reg,
-                                SIRFUART_RX_IO_INT_EN(uint_en,
-                                        sirfport->uart_reg->uart_type));
-        }
-}
-
 static unsigned int
 sirfsoc_usp_calc_sample_div(unsigned long set_rate,
                 unsigned long ioclk_rate, unsigned long *sample_reg)
@@ -850,7 +823,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
         rx_time_out = SIRFSOC_UART_RX_TIMEOUT(set_baud, 20000);
         rx_time_out = SIRFUART_RECV_TIMEOUT_VALUE(rx_time_out);
         txfifo_op_reg = rd_regl(port, ureg->sirfsoc_tx_fifo_op);
-        wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_STOP);
         wr_regl(port, ureg->sirfsoc_tx_fifo_op,
                         (txfifo_op_reg & ~SIRFUART_FIFO_START));
         if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
@@ -906,7 +878,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
         txfifo_op_reg |= SIRFUART_FIFO_START;
         wr_regl(port, ureg->sirfsoc_tx_fifo_op, txfifo_op_reg);
         uart_update_timeout(port, termios->c_cflag, set_baud);
-        sirfsoc_uart_start_rx(port);
         wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_TX_EN | SIRFUART_RX_EN);
         spin_unlock_irqrestore(&port->lock, flags);
 }
@@ -925,6 +896,7 @@ static int sirfsoc_uart_startup(struct uart_port *port)
 {
         struct sirfsoc_uart_port *sirfport      = to_sirfport(port);
         struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
+        struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
         unsigned int index                      = port->line;
         int ret;
         irq_modify_status(port->irq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
@@ -994,7 +966,6 @@ static int sirfsoc_uart_startup(struct uart_port *port)
                 wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
                         rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
                         SIRFSOC_USP_FRADDR_CLR_EN);
-        enable_irq(port->irq);
         if (sirfport->rx_dma_chan && !sirfport->is_hrt_enabled) {
                 sirfport->is_hrt_enabled = true;
                 sirfport->rx_period_time = 20000000;
@@ -1006,6 +977,21 @@ static int sirfsoc_uart_startup(struct uart_port *port)
                         ns_to_ktime(sirfport->rx_period_time),
                         HRTIMER_MODE_REL);
         }
+        wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
+        if (sirfport->rx_dma_chan)
+                sirfsoc_uart_start_next_rx_dma(port);
+        else {
+                if (!sirfport->is_atlas7)
+                        wr_regl(port, ureg->sirfsoc_int_en_reg,
+                                rd_regl(port, ureg->sirfsoc_int_en_reg) |
+                                SIRFUART_RX_IO_INT_EN(uint_en,
+                                        sirfport->uart_reg->uart_type));
+                else
+                        wr_regl(port, ureg->sirfsoc_int_en_reg,
+                                SIRFUART_RX_IO_INT_EN(uint_en,
+                                        sirfport->uart_reg->uart_type));
+        }
+        enable_irq(port->irq);
 
         return 0;
 init_rx_err: