From: Barry Song <21cnbao@gmail.com>
To: gregkh@linuxfoundation.org, linux-serial@vger.kernel.org
Cc: Qipan Li <Qipan.Li@csr.com>,
workgroup.linux@csr.com, linux-arm-kernel@lists.infradead.org,
Barry Song <Baohua.Song@csr.com>
Subject: [PATCH 2/2] serial: sirf: let uart's receive start in right place
Date: Tue, 14 Jul 2015 00:52:23 +0000 [thread overview]
Message-ID: <1436835143-6697-2-git-send-email-21cnbao@gmail.com> (raw)
In-Reply-To: <1436835143-6697-1-git-send-email-21cnbao@gmail.com>
From: Qipan Li <Qipan.Li@csr.com>
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>
---
drivers/tty/serial/sirfsoc_uart.c | 46 ++++++++++++++-------------------------
drivers/tty/serial/sirfsoc_uart.h | 1 -
2 files changed, 16 insertions(+), 31 deletions(-)
diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 8cac7ac..c6657de 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:
diff --git a/drivers/tty/serial/sirfsoc_uart.h b/drivers/tty/serial/sirfsoc_uart.h
index 671a08d..c3a885b 100644
--- a/drivers/tty/serial/sirfsoc_uart.h
+++ b/drivers/tty/serial/sirfsoc_uart.h
@@ -423,7 +423,6 @@ struct sirfsoc_uart_port {
struct dma_chan *tx_dma_chan;
dma_addr_t tx_dma_addr;
struct dma_async_tx_descriptor *tx_dma_desc;
- unsigned int rx_io_count;
unsigned long transfer_size;
enum sirfsoc_tx_state tx_dma_state;
unsigned int cts_gpio;
--
2.3.5
prev parent reply other threads:[~2015-07-14 0:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-14 0:52 [PATCH 1/2] serial: sirf: workaround rx process to avoid possible data loss Barry Song
2015-07-14 0:52 ` Barry Song [this message]
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