From fb8d832978bb68853c082f02985253fb2f345f69 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 10 Jul 2020 15:59:46 +0200 Subject: [PATCH] serial: tegra: fix CREAD handling for PIO commit b374c562ee7ab3f3a1daf959c01868bae761571c upstream. Commit 33ae787b74fc ("serial: tegra: add support to ignore read") added support for dropping input in case CREAD isn't set, but for PIO the ignore_status_mask wasn't checked until after the character had been put in the receive buffer. Note that the NULL tty-port test is bogus and will be removed by a follow-on patch. Fixes: 33ae787b74fc ("serial: tegra: add support to ignore read") Cc: stable # 5.4 Cc: Shardar Shariff Md Cc: Krishna Yarlagadda Signed-off-by: Johan Hovold Acked-by: Thierry Reding Link: https://lore.kernel.org/r/20200710135947.2737-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial-tegra.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index 2f599515c133..51c3f579ccd0 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -651,11 +651,14 @@ static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup, ch = (unsigned char) tegra_uart_read(tup, UART_RX); tup->uport.icount.rx++; - if (!uart_handle_sysrq_char(&tup->uport, ch) && tty) - tty_insert_flip_char(tty, ch, flag); + if (uart_handle_sysrq_char(&tup->uport, ch)) + continue; if (tup->uport.ignore_status_mask & UART_LSR_DR) continue; + + if (tty) + tty_insert_flip_char(tty, ch, flag); } while (1); }