From: bigeasy@linutronix.de (Sebastian Andrzej Siewior)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 10/18] tty: serial: 8250_dma: enqueue RX dma again on completion.
Date: Fri, 5 Sep 2014 21:02:45 +0200 [thread overview]
Message-ID: <1409943773-7874-11-git-send-email-bigeasy@linutronix.de> (raw)
In-Reply-To: <1409943773-7874-1-git-send-email-bigeasy@linutronix.de>
The omap needs a DMA request pending right away. If it is enqueued once
the bytes are in the FIFO then nothing will happen and the FIFO will be
later purged via RX-timeout interrupt.
This patch enqueues RX-DMA request on completion but not if it was
aborted on error. The first enqueue will happen in the driver in
startup.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/tty/serial/8250/8250.h | 3 ++-
drivers/tty/serial/8250/8250_core.c | 3 +++
drivers/tty/serial/8250/8250_dma.c | 12 +++++++++---
3 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index a63d198f8d03..fbed1636e9c4 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -80,7 +80,8 @@ struct serial8250_config {
#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
#define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */
-
+#define UART_BUG_DMA_RX (1 << 5) /* UART needs DMA RX req before there is
+ data in FIFO */
#define PROBE_RSA (1 << 0)
#define PROBE_ANY (~0)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 2101134e5031..079048db8c81 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1590,6 +1590,9 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
if (!up->dma || dma_err)
status = serial8250_rx_chars(up, status);
+
+ if (dma_err && up->bugs & UART_BUG_DMA_RX)
+ serial8250_rx_dma(up, 0);
}
serial8250_modem_status(up);
if ((!up->dma || (up->dma && up->dma->tx_err)) &&
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 69e54abb6e71..3674900a1f14 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -50,9 +50,8 @@ static void __dma_tx_complete(void *param)
spin_unlock_irqrestore(&p->port.lock, flags);
}
-static void __dma_rx_complete(void *param)
+static void __dma_rx_do_complete(struct uart_8250_port *p, bool error)
{
- struct uart_8250_port *p = param;
struct uart_8250_dma *dma = p->dma;
struct tty_port *tty_port = &p->port.state->port;
struct dma_tx_state state;
@@ -68,10 +67,17 @@ static void __dma_rx_complete(void *param)
tty_insert_flip_string(tty_port, dma->rx_buf, count);
p->port.icount.rx += count;
+ if (!error && p->bugs & UART_BUG_DMA_RX)
+ serial8250_rx_dma(p, 0);
tty_flip_buffer_push(tty_port);
}
+static void __dma_rx_complete(void *param)
+{
+ __dma_rx_do_complete(param, false);
+}
+
int serial8250_tx_dma(struct uart_8250_port *p)
{
struct uart_8250_dma *dma = p->dma;
@@ -139,7 +145,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
*/
if (dma_status == DMA_IN_PROGRESS) {
dmaengine_pause(dma->rxchan);
- __dma_rx_complete(p);
+ __dma_rx_do_complete(p, true);
}
return -ETIMEDOUT;
default:
--
2.1.0
next prev parent reply other threads:[~2014-09-05 19:02 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-05 19:02 [PATCH v8 00/18] 8250-core based serial driver for OMAP + DMA Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 01/18] tty: serial: 8250_core: provide a function to export uart_8250_port Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 02/18] tty: serial: 8250_core: allow to overwrite & export serial8250_startup() Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 03/18] tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks Sebastian Andrzej Siewior
2014-09-08 23:33 ` Greg Kroah-Hartman
2014-09-09 0:41 ` Tony Lindgren
2014-09-05 19:02 ` [PATCH 04/18] tty: serial: 8250_core: add run time pm Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 05/18] tty: serial: 8250_core: read only RX if there is something in the FIFO Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 06/18] tty: serial: 8250_core: user the ->line argument as a hint in serial8250_find_match_or_unused() Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 07/18] tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx() Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 08/18] tty: serial: Add 8250-core based omap driver Sebastian Andrzej Siewior
2014-09-08 16:39 ` Tony Lindgren
2014-09-05 19:02 ` [PATCH 09/18] tty: serial: 8250_dma: handle error on TX submit Sebastian Andrzej Siewior
2014-09-05 19:02 ` Sebastian Andrzej Siewior [this message]
2014-09-05 19:02 ` [PATCH 11/18] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx Sebastian Andrzej Siewior
2014-09-08 16:41 ` Tony Lindgren
2014-09-08 16:45 ` Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 12/18] tty: serial: 8250_dma: optimize the xmit path due to UART_BUG_DMA_TX Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 13/18] tty: serial: 8250_dma: keep own book keeping about RX transfers Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 14/18] tty: serial: 8250_dma: handle the when UART response while DMA remains idle Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 15/18] tty: serial: 8250_dma: add pm runtime Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 16/18] arm: dts: am33xx: add DMA properties for UART Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 17/18] arm: dts: dra7: " Sebastian Andrzej Siewior
2014-09-05 19:02 ` [PATCH 18/18] tty: serial: 8250: omap: add dma support Sebastian Andrzej Siewior
2014-09-08 14:46 ` [PATCH v8 00/18] 8250-core based serial driver for OMAP + DMA Frans Klaver
2014-09-08 15:15 ` Sebastian Andrzej Siewior
2014-09-08 16:33 ` Sebastian Andrzej Siewior
2014-09-08 18:25 ` Frans Klaver
2014-09-08 18:33 ` Frans Klaver
2014-09-09 19:41 ` Sebastian Andrzej Siewior
2014-09-10 14:15 ` Frans Klaver
2014-09-10 16:56 ` Sebastian Andrzej Siewior
2014-09-08 17:40 ` Tony Lindgren
2014-09-08 17:55 ` Tony Lindgren
2014-09-09 7:33 ` Sebastian Andrzej Siewior
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