2019-09-04 04:44:26

by Krishna Yarlagadda

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

From: Shardar Shariff Md <[email protected]>

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

Signed-off-by: Shardar Shariff Md <[email protected]>
Signed-off-by: Krishna Yarlagadda <[email protected]>
---
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