[PATCH 2/3] serial: 8250_omap: check how many bytes were injected
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2015-08-14 16:01:24
Also in:
linux-omap, lkml
Subsystem:
8250/16?50 (and clone uarts) serial driver, the rest, tty layer and serial drivers · Maintainers:
Greg Kroah-Hartman, Linus Torvalds, Jiri Slaby
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