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

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Message-Id: <20231026-mbly-uart-v1-6-9258eea297d3@bootlin.com>
Date:   Thu, 26 Oct 2023 12:41:23 +0200
From:   Théo Lebrun <theo.lebrun@...tlin.com>
To:     Russell King <linux@...linux.org.uk>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Gregory CLEMENT <gregory.clement@...tlin.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Vladimir Kondratiev <vladimir.kondratiev@...ileye.com>,
        Tawfik Bayouk <tawfik.bayouk@...ileye.com>,
        Théo Lebrun <theo.lebrun@...tlin.com>
Subject: [PATCH 6/6] tty: serial: amba-pl011: Parse bits option as 5, 6, 7
 or 8 in _get_options

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@...tlin.com>
---
 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