Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755576AbbHNQBY (ORCPT ); Fri, 14 Aug 2015 12:01:24 -0400 Received: from www.linutronix.de ([62.245.132.108]:47258 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755424AbbHNQBT (ORCPT ); Fri, 14 Aug 2015 12:01:19 -0400 From: Sebastian Andrzej Siewior To: peter@hurleysoftware.com Cc: linux-kernel@vger.kernel.org, nsekhar@ti.com, linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, john.ogness@linutronix.de, Sebastian Andrzej Siewior , Greg Kroah-Hartman Subject: [PATCH 2/3] serial: 8250_omap: check how many bytes were injected Date: Fri, 14 Aug 2015 18:01:03 +0200 Message-Id: <1439568064-7907-2-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1439568064-7907-1-git-send-email-bigeasy@linutronix.de> References: <1439568064-7907-1-git-send-email-bigeasy@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 46 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 Signed-off-by: Sebastian Andrzej Siewior --- 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/