[PATCH v2 01/10] serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled

Path	csiph.com!1.us.feeder.erje.net!2.us.feeder.erje.net!feeder.erje.net!1.eu.feeder.erje.net!weretis.net!feeder4.news.weretis.net!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod
From	Lee Jones <lee.jones@linaro.org>
Newsgroups	linux.kernel
Subject	[PATCH v2 01/10] serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled
Date	Wed, 01 Feb 2017 15:40:02 +0100
Message-ID	<t64eK-77f-23@gated-at.bofh.it> (permalink)
References	<t64eJ-77f-5@gated-at.bofh.it>
Dkim-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hlKrZUbdZb3ODtd0dth/ItQyMint0+JkHFNCQC/C7kc=; b=RfPAtTP+EnH0ppPKWtAtdufrnNgPQOFwH97t7k2f8K+D8qcF8rWR4hLg4GW2/W3Ps6 ThAAwMqEUUxjyKlm5d5AotSLqXi8cB3eCGbyssxp0Zqj0sIf+dspIltSff8luToNHP4P mwvSgFfJMhre5S5uIVlj5r+pth24RKl5HS9uE=
X-Google-Dkim-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hlKrZUbdZb3ODtd0dth/ItQyMint0+JkHFNCQC/C7kc=; b=RgYgJqruTvWiBb/hFBBqTvMbRqw/qEYfY7eDV8gyvVmxjYI5f9bMeSAaTLSsP2pZ9V wQMvDHtnLh0Yw6TUWpfp+oZjdz9fDMXpaaze1p3+L8ePtp3CWMGqqiUvAQEoR1Jq2rH5 neY/pZz4Qo5lhsmfTih07+lHtkHO2zKNQ9F03lMVeCsb+8vC2vXhwlorRbxcboWYFfd/ m+MetHRtk4JWyVeZungs+SSmw+ntHHQQVYZ3AL3Gc5354G3Zlj+8gOgu1rfjmpcZSeMo qTCP1ANemC2JNqOnu2hbiDUatuPy+TkF32sJ1YncD8ohAnQP8GuMSFOVEfHPmz6t6TyX hLzQ==
X-Gm-Message-State	AIkVDXIEdjFjqdlibRrY9N1ZYlQu3290mftwPQFYKwB3xIou0hr2EYBQr6fokTiyW3Dl3HTS
X-Received	by 10.223.139.142 with SMTP id o14mr2990636wra.6.1485959512200; Wed, 01 Feb 2017 06:31:52 -0800 (PST)
X-Mailer	git-send-email 2.9.3
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	49
Organization	linux.* mail to news gateway
X-Original-Cc	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@stlinux.com, patrice.chotard@st.com, Lee Jones <lee.jones@linaro.org>
X-Original-Date	Wed, 1 Feb 2017 14:31:36 +0000
X-Original-Message-ID	<20170201143145.31962-2-lee.jones@linaro.org>
X-Original-References	<20170201143145.31962-1-lee.jones@linaro.org>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1571590

Show key headers only | View raw

The datasheet states:

"If the MODE field selects an 8-bit frame then this [parity error] bit
 is undefined. Software should ignore this bit when reading 8-bit frames."

Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/tty/serial/st-asc.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index 379e5bd..69e6232 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -287,9 +287,19 @@ static void asc_transmit_chars(struct uart_port *port)
 static void asc_receive_chars(struct uart_port *port)
 {
 	struct tty_port *tport = &port->state->port;
-	unsigned long status;
+	unsigned long status, mode;
 	unsigned long c = 0;
 	char flag;
+	bool ignore_pe = false;
+
+	/*
+	 * Datasheet states: If the MODE field selects an 8-bit frame then
+	 * this [parity error] bit is undefined. Software should ignore this
+	 * bit when reading 8-bit frames.
+	 */
+	mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK;
+	if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR)
+		ignore_pe = true;
 
 	if (port->irq_wake)
 		pm_wakeup_event(tport->tty->dev, 0);
@@ -299,8 +309,8 @@ static void asc_receive_chars(struct uart_port *port)
 		flag = TTY_NORMAL;
 		port->icount.rx++;
 
-		if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) ||
-			status & ASC_STA_OE) {
+		if (status & ASC_STA_OE || c & ASC_RXBUF_FE ||
+		    (c & ASC_RXBUF_PE && !ignore_pe)) {
 
 			if (c & ASC_RXBUF_FE) {
 				if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
-- 
2.9.3

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH v2 01/10] serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled Lee Jones <lee.jones@linaro.org> - 2017-02-01 15:40 +0100

csiph-web