From 33ae787b74fc0e1dfe6bb998c7e4d1c2369a8776 Mon Sep 17 00:00:00 2001 From: Shardar Shariff Md Date: Wed, 4 Sep 2019 10:12:56 +0530 Subject: [PATCH] serial: tegra: add support to ignore read Add support to ignore read characters if CREAD flag is not set. Signed-off-by: Shardar Shariff Md Signed-off-by: Krishna Yarlagadda Link: https://lore.kernel.org/r/1567572187-29820-2-git-send-email-kyarlagadda@nvidia.com Signed-off-by: Greg Kroah-Hartman --- 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); } -- 2.20.1