[PATCH V2 01/12] serial: tegra: add support to ignore read

[Krishna Yarlagadda]

From: Shardar Shariff Md <smoham...@nvidia.com>

Add support to ignore read characters if CREAD flag is not set.

Signed-off-by: Shardar Shariff Md <smoham...@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlaga...@nvidia.com>
---
 drivers/tty/serial/serial-tegra.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/tty/serial/serial-tegra.c 
b/drivers/tty/serial/serial-tegra.c
index 82a8d51..9c15c87 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -547,6 +547,9 @@ static void tegra_uart_handle_rx_pio(struct tegra_uart_port 
*tup,
 
                if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
                        tty_insert_flip_char(tty, ch, flag);
+
+               if (tup->uport.ignore_status_mask & UART_LSR_DR)
+                       continue;
        } while (1);
 }
 
@@ -565,6 +568,10 @@ static void tegra_uart_copy_rx_to_tty(struct 
tegra_uart_port *tup,
                dev_err(tup->uport.dev, "No tty port\n");
                return;
        }
+
+       if (tup->uport.ignore_status_mask & UART_LSR_DR)
+               return;
+
        dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
                                TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
        copied = tty_insert_flip_string(tty,
@@ -1193,6 +1200,11 @@ static void tegra_uart_set_termios(struct uart_port *u,
        tegra_uart_write(tup, tup->ier_shadow, UART_IER);
        tegra_uart_read(tup, UART_IER);
 
+       tup->uport.ignore_status_mask = 0;
+       /* Ignore all characters if CREAD is not set */
+       if ((termios->c_cflag & CREAD) == 0)
+               tup->uport.ignore_status_mask |= UART_LSR_DR;
+
        spin_unlock_irqrestore(&u->lock, flags);
 }
 
-- 
2.7.4