Blackfin Serial Driver: Fix bug - update tx dma buffer tail before wake up processes.
Also make rx dma buffer work as a loop.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 2fb3081..2a41174 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -415,7 +415,6 @@
*/
bfin_serial_mctrl_check(uart);
- spin_lock_irqsave(&uart->port.lock, flags);
uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
uart->tx_count = UART_XMIT_SIZE - xmit->tail;
@@ -439,7 +438,6 @@
ier |= ETBEI;
UART_PUT_IER(uart, ier);
#endif
- spin_unlock_irqrestore(&uart->port.lock, flags);
}
static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
@@ -450,7 +448,9 @@
status = UART_GET_LSR(uart);
UART_CLEAR_LSR(uart);
- uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
+ uart->port.icount.rx +=
+ CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
+ UART_XMIT_SIZE);
if (status & BI) {
uart->port.icount.brk++;
@@ -476,10 +476,12 @@
else
flg = TTY_NORMAL;
- for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
- if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
- goto dma_ignore_char;
- uart_insert_char(&uart->port, status, OE, uart->rx_dma_buf.buf[i], flg);
+ for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {
+ if (i >= UART_XMIT_SIZE)
+ i = 0;
+ if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
+ uart_insert_char(&uart->port, status, OE,
+ uart->rx_dma_buf.buf[i], flg);
}
dma_ignore_char:
@@ -492,16 +494,20 @@
int flags = 0;
spin_lock_irqsave(&uart->port.lock, flags);
- x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
+ uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
+ x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
+ uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
+ if (uart->rx_dma_nrows == DMA_RX_YCOUNT)
+ uart->rx_dma_nrows = 0;
+ x_pos = DMA_RX_XCOUNT - x_pos;
if (x_pos == DMA_RX_XCOUNT)
x_pos = 0;
pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
-
- if (pos>uart->rx_dma_buf.tail) {
- uart->rx_dma_buf.tail = pos;
+ if (pos != uart->rx_dma_buf.tail) {
+ uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
- uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+ uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
spin_unlock_irqrestore(&uart->port.lock, flags);
uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
@@ -525,12 +531,12 @@
ier &= ~ETBEI;
UART_PUT_IER(uart, ier);
#endif
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&uart->port);
-
xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx += uart->tx_count;
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uart->port);
+
bfin_serial_dma_tx_chars(uart);
}
@@ -542,15 +548,16 @@
{
struct bfin_serial_port *uart = dev_id;
unsigned short irqstat;
+ int pos;
- uart->rx_dma_nrows++;
- uart->rx_dma_buf.tail = DMA_RX_XCOUNT * uart->rx_dma_nrows;
- bfin_serial_dma_rx_chars(uart);
- if (uart->rx_dma_nrows >= DMA_RX_YCOUNT) {
- uart->rx_dma_nrows = 0;
- uart->rx_dma_buf.tail = 0;
+ uart->rx_dma_nrows = DMA_RX_YCOUNT -
+ get_dma_curr_ycount(uart->rx_dma_channel);
+ pos = DMA_RX_XCOUNT * uart->rx_dma_nrows;
+ if (pos != uart->rx_dma_buf.tail) {
+ uart->rx_dma_buf.head = pos;
+ bfin_serial_dma_rx_chars(uart);
+ uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
- uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
spin_lock(&uart->port.lock);
irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);