Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1207596

[PATCH 2/3] serial: 8250_omap: check how many bytes were injected

From Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Newsgroups linux.kernel
Subject [PATCH 2/3] serial: 8250_omap: check how many bytes were injected
Date 2015-08-14 18:10 +0200
Message-ID <pXpIm-6Yn-3@gated-at.bofh.it> (permalink)
References <pXpIm-6Yn-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


The function tty_insert_flip_string() returns an int and as such it
might fail. So the result is that I kindly asked to insert 48 bytes and
the function only insterted 32.
I have no idea what to do with the remaining 16 so I think dropping them
is the only option. I also increase the buf_overrun counter so userpace
has a clue that we lost bytes.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/tty/serial/8250/8250_omap.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 2ac63c8bd946..933f7ef2c004 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -738,6 +738,7 @@ static void __dma_rx_do_complete(struct uart_8250_port *p, bool error)
 	struct dma_tx_state     state;
 	int                     count;
 	unsigned long		flags;
+	int			ret;
 
 	dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
 				dma->rx_size, DMA_FROM_DEVICE);
@@ -753,8 +754,10 @@ static void __dma_rx_do_complete(struct uart_8250_port *p, bool error)
 
 	count = dma->rx_size - state.residue;
 
-	tty_insert_flip_string(tty_port, dma->rx_buf, count);
-	p->port.icount.rx += count;
+	ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
+
+	p->port.icount.rx += ret;
+	p->port.icount.buf_overrun += count - ret;
 unlock:
 	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
 
-- 
2.5.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

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


Thread

[PATCH 1/3] serial: 8250: move rx_running out of the bitfield Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2015-08-14 18:10 +0200
  [PATCH 2/3] serial: 8250_omap: check how many bytes were injected Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2015-08-14 18:10 +0200
  [RFC 3/3] serial: 8250_omap: try to avoid IER_RDI with DMA Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2015-08-14 18:10 +0200

csiph-web