From: Shardar Shariff Md <smohammed@nvidia.com>
Date: Wed, 4 Sep 2019 10:12:56 +0530
Subject: serial: tegra: add support to ignore read
Git-commit: 33ae787b74fc0e1dfe6bb998c7e4d1c2369a8776
Patch-mainline: v5.4-rc1
References: jsc#SLE-9391,jsc#SLE-9388,jsc#SLE-10608
Add support to ignore read characters if CREAD flag is not set.
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Link: https://lore.kernel.org/r/1567572187-29820-2-git-send-email-kyarlagadda@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.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 82a8d5130cbc..9c15c87fa9e5 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);
}
--
2.16.4