[PATCH 6/6] tty: serial: amba-pl011: Parse bits option as 5, 6, 7 or 8 in _get_options

From: Théo Lebrun
Date: Thu Oct 26 2023 - 06:42:19 EST


pl011_console_get_options() gets called to retrieve currently configured
options from the registers. Previously, LCRH_TX.WLEN was being parsed
as either 7 or 8 (fallback). Hardware supports values from 5 to 8
inclusive, which pl011_set_termios() exploits for example.

Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 5774d48c7f16..b2062e4cbbab 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2384,10 +2384,7 @@ static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
*parity = 'o';
}

- if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
- *bits = 7;
- else
- *bits = 8;
+ *bits = FIELD_GET(0x60, lcr_h) + 5; /* from 5 to 8 inclusive */

ibrd = pl011_read(uap, REG_IBRD);
fbrd = pl011_read(uap, REG_FBRD);

--
2.41.0