diff options
Diffstat (limited to 'drivers/serial/bfin_5xx.c')
| -rw-r--r-- | drivers/serial/bfin_5xx.c | 77 |
1 files changed, 67 insertions, 10 deletions
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c index d86123e0339..e2f6b1bfac9 100644 --- a/drivers/serial/bfin_5xx.c +++ b/drivers/serial/bfin_5xx.c @@ -330,6 +330,11 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart) /* Clear TFI bit */ UART_PUT_LSR(uart, TFI); #endif + /* Anomaly notes: + * 05000215 - we always clear ETBEI within last UART TX + * interrupt to end a string. It is always set + * when start a new tx. + */ UART_CLEAR_IER(uart, ETBEI); return; } @@ -415,6 +420,7 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail)); set_dma_x_count(uart->tx_dma_channel, uart->tx_count); set_dma_x_modify(uart->tx_dma_channel, 1); + SSYNC(); enable_dma(uart->tx_dma_channel); UART_SET_IER(uart, ETBEI); @@ -473,27 +479,41 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart) void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart) { int x_pos, pos; - unsigned long flags; - - spin_lock_irqsave(&uart->port.lock, flags); + dma_disable_irq(uart->rx_dma_channel); + spin_lock_bh(&uart->port.lock); + + /* 2D DMA RX buffer ring is used. Because curr_y_count and + * curr_x_count can't be read as an atomic operation, + * curr_y_count should be read before curr_x_count. When + * curr_x_count is read, curr_y_count may already indicate + * next buffer line. But, the position calculated here is + * still indicate the old line. The wrong position data may + * be smaller than current buffer tail, which cause garbages + * are received if it is not prohibit. + */ 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) + if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0) 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) { + /* Ignore receiving data if new position is in the same line of + * current buffer tail and small. + */ + if (pos > uart->rx_dma_buf.tail || + uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) { uart->rx_dma_buf.head = pos; bfin_serial_dma_rx_chars(uart); uart->rx_dma_buf.tail = uart->rx_dma_buf.head; } - spin_unlock_irqrestore(&uart->port.lock, flags); + spin_unlock_bh(&uart->port.lock); + dma_enable_irq(uart->rx_dma_channel); mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES); } @@ -514,6 +534,11 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id) if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) { disable_dma(uart->tx_dma_channel); clear_dma_irqstat(uart->tx_dma_channel); + /* Anomaly notes: + * 05000215 - we always clear ETBEI within last UART TX + * interrupt to end a string. It is always set + * when start a new tx. + */ UART_CLEAR_IER(uart, ETBEI); xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1); uart->port.icount.tx += uart->tx_count; @@ -532,11 +557,26 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id) { struct bfin_serial_port *uart = dev_id; unsigned short irqstat; + int x_pos, pos; spin_lock(&uart->port.lock); irqstat = get_dma_curr_irqstat(uart->rx_dma_channel); clear_dma_irqstat(uart->rx_dma_channel); - bfin_serial_dma_rx_chars(uart); + + 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 || x_pos == 0) + uart->rx_dma_nrows = 0; + + pos = uart->rx_dma_nrows * DMA_RX_XCOUNT; + if (pos > uart->rx_dma_buf.tail || + uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) { + uart->rx_dma_buf.head = pos; + bfin_serial_dma_rx_chars(uart); + uart->rx_dma_buf.tail = uart->rx_dma_buf.head; + } + spin_unlock(&uart->port.lock); return IRQ_HANDLED; @@ -789,8 +829,16 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios, __func__); } - if (termios->c_cflag & CSTOPB) - lcr |= STB; + /* Anomaly notes: + * 05000231 - STOP bit is always set to 1 whatever the user is set. + */ + if (termios->c_cflag & CSTOPB) { + if (ANOMALY_05000231) + printk(KERN_WARNING "STOP bits other than 1 is not " + "supported in case of anomaly 05000231.\n"); + else + lcr |= STB; + } if (termios->c_cflag & PARENB) lcr |= PEN; if (!(termios->c_cflag & PARODD)) @@ -940,6 +988,10 @@ static void bfin_serial_reset_irda(struct uart_port *port) } #ifdef CONFIG_CONSOLE_POLL +/* Anomaly notes: + * 05000099 - Because we only use THRE in poll_put and DR in poll_get, + * losing other bits of UART_LSR is not a problem here. + */ static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr) { struct bfin_serial_port *uart = (struct bfin_serial_port *)port; @@ -1245,12 +1297,17 @@ static __init void early_serial_write(struct console *con, const char *s, } } +/* + * This should have a .setup or .early_setup in it, but then things get called + * without the command line options, and the baud rate gets messed up - so + * don't let the common infrastructure play with things. (see calls to setup + * & earlysetup in ./kernel/printk.c:register_console() + */ static struct __initdata console bfin_early_serial_console = { .name = "early_BFuart", .write = early_serial_write, .device = uart_console_device, .flags = CON_PRINTBUFFER, - .setup = bfin_serial_console_setup, .index = -1, .data = &bfin_serial_reg, }; |