| Message ID | 1439568064-7907-2-git-send-email-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Friday 14 August 2015 09:31 PM, Sebastian Andrzej Siewior wrote: > 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> Tested with wilink BT module on TI's DRA7 EVM. Tested-by: Sekhar Nori <nsekhar@ti.com> Thanks, Sekhar -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/14/2015 12:01 PM, Sebastian Andrzej Siewior wrote: > 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. No objection to the patch but I'm curious whether this is something you've actually observed and under what circumstances. Regards, Peter Hurley > 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); > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday 26 August 2015 06:14 PM, Peter Hurley wrote: > On 08/14/2015 12:01 PM, Sebastian Andrzej Siewior wrote: >> 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. > > No objection to the patch but I'm curious whether this is something you've > actually observed and under what circumstances. This was observed while doing a UART internal loopback test at 3Mbaud on TI's DRA7 EVM. Thanks, Sekhar -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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);
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(-)