From: Krishna Yarlagadda <kyarlagadda@nvidia.com>
To: <gregkh@linuxfoundation.org>, <robh+dt@kernel.org>,
<mark.rutland@arm.com>, <thierry.reding@gmail.com>,
<jonathanh@nvidia.com>, <ldewangan@nvidia.com>, <jslaby@suse.com>
Cc: <linux-serial@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Shardar Shariff Md <smohammed@nvidia.com>,
Krishna Yarlagadda <kyarlagadda@nvidia.com>
Subject: [PATCH 05/14] serial: tegra: flush the RX fifo on frame error
Date: Mon, 12 Aug 2019 16:58:14 +0530 [thread overview]
Message-ID: <1565609303-27000-6-git-send-email-kyarlagadda@nvidia.com> (raw)
In-Reply-To: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com>
From: Shardar Shariff Md <smohammed@nvidia.com>
FIFO reset/flush code implemented now does not follow programming
guidelines. RTS line has to be turned off while flushing fifos to
avoid new transfers. Also check LSR bits UART_LSR_TEMT and UART_LSR_DR
to confirm fifos are flushed.
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
drivers/tty/serial/serial-tegra.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index ae7225c..f6a3f4e 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -266,6 +266,10 @@ static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
{
unsigned long fcr = tup->fcr_shadow;
+ unsigned int lsr, tmout = 10000;
+
+ if (tup->rts_active)
+ set_rts(tup, false);
if (tup->cdata->allow_txfifo_reset_fifo_mode) {
fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
@@ -289,6 +293,17 @@ static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
* to propagate, otherwise data could be lost.
*/
tegra_uart_wait_cycle_time(tup, 32);
+
+ do {
+ lsr = tegra_uart_read(tup, UART_LSR);
+ if (lsr | UART_LSR_TEMT)
+ if (!(lsr & UART_LSR_DR))
+ break;
+ udelay(1);
+ } while (--tmout);
+
+ if (tup->rts_active)
+ set_rts(tup, true);
}
static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
--
2.7.4
next prev parent reply other threads:[~2019-08-12 11:28 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 11:28 [PATCH 00/14] serial: tegra: Tegra186 support and fixes Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 01/14] serial: tegra: add internal loopback functionality Krishna Yarlagadda
2019-08-13 9:38 ` Thierry Reding
2019-08-12 11:28 ` [PATCH 02/14] serial: tegra: add support to ignore read Krishna Yarlagadda
2019-08-13 9:42 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 03/14] serial: tegra: avoid reg access when clk disabled Krishna Yarlagadda
2019-08-13 9:45 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 04/14] serial: tegra: protect IER against LCR.DLAB Krishna Yarlagadda
2019-08-13 9:46 ` Thierry Reding
2019-08-12 11:28 ` Krishna Yarlagadda [this message]
2019-08-13 9:48 ` [PATCH 05/14] serial: tegra: flush the RX fifo on frame error Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 06/14] serial: tegra: report error to upper tty layer Krishna Yarlagadda
2019-08-13 9:52 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 07/14] serial: tegra: add compatible for new chips Krishna Yarlagadda
2019-08-13 9:55 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 08/14] serial: tegra: check for FIFO mode enabled status Krishna Yarlagadda
2019-08-13 10:03 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 09/14] serial: tegra: set maximum num of uart ports to 8 Krishna Yarlagadda
2019-08-13 10:19 ` Thierry Reding
2019-08-27 9:30 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 10/14] serial: tegra: add support to use 8 bytes trigger Krishna Yarlagadda
2019-08-19 20:29 ` Jon Hunter
2019-08-27 9:31 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 11/14] serial: tegra: DT for Adjusted baud rates Krishna Yarlagadda
2019-08-13 10:24 ` Thierry Reding
2019-08-27 9:31 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 12/14] serial: tegra: add support to adjust baud rate Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 13/14] serial: tegra: report clk rate errors Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 14/14] serial: tegra: Add PIO mode support Krishna Yarlagadda
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