linux-kernel - [PATCH 2/4] tty: serial: samsung: Properly set flags in autoCTS mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <20181214113410.22848-3-m.szyprowski@samsung.com>
Date:   Fri, 14 Dec 2018 12:34:08 +0100
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org
Cc:     Marek Szyprowski <m.szyprowski@...sung.com>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Beomho Seo <beomho.seo@...sung.com>,
        Seung-Woo Kim <sw0312.kim@...sung.com>,
        Sylwester Nawrocki <s.nawrocki@...sung.com>,
        Lee Jones <lee.jones@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH 2/4] tty: serial: samsung: Properly set flags in autoCTS
 mode

From: Beomho Seo <beomho.seo@...sung.com>

Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support")
has changed the way the autoCTS mode is handled.

According to that change, serial drivers which enable H/W autoCTS mode must
set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling
TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.

Signed-off-by: Beomho Seo <beomho.seo@...sung.com>
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@...sung.com>
---
 drivers/tty/serial/samsung.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index da1bd4bba8a9..2a49b6d876b8 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1365,11 +1365,14 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	wr_regl(port, S3C2410_ULCON, ulcon);
 	wr_regl(port, S3C2410_UBRDIV, quot);
 
+	port->status &= ~UPSTAT_AUTOCTS;
+
 	umcon = rd_regl(port, S3C2410_UMCON);
 	if (termios->c_cflag & CRTSCTS) {
 		umcon |= S3C2410_UMCOM_AFC;
 		/* Disable RTS when RX FIFO contains 63 bytes */
 		umcon &= ~S3C2412_UMCON_AFC_8;
+		port->status = UPSTAT_AUTOCTS;
 	} else {
 		umcon &= ~S3C2410_UMCOM_AFC;
 	}
-- 
2.17.1