Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760071AbYAaPHf (ORCPT ); Thu, 31 Jan 2008 10:07:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753336AbYAaPHZ (ORCPT ); Thu, 31 Jan 2008 10:07:25 -0500 Received: from nat-132.atmel.no ([80.232.32.132]:52259 "EHLO relay.atmel.no" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753241AbYAaPHY (ORCPT ); Thu, 31 Jan 2008 10:07:24 -0500 Date: Thu, 31 Jan 2008 16:07:21 +0100 From: Haavard Skinnemoen To: michael Cc: Remy Bohmer , fabio@gandalf.sssup.it, Andrew Victor , Chip Coldwell , Marc Pignat , David Brownell , linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [PATCH -mm v4 6/9] atmel_serial: Split the interrupt handler Message-ID: <20080131160721.6dddf30e@dhcp-252-066.norway.atmel.com> In-Reply-To: <47A12A2E.5040309@gandalf.sssup.it> References: <20080129224316.GA23155@gandalf.sssup.it> <479FB2D7.4020804@gandalf.sssup.it> <20080130104113.48ec376f@dhcp-252-066.norway.atmel.com> <47A051A7.7030004@gandalf.sssup.it> <20080130133659.55ebd828@dhcp-252-066.norway.atmel.com> <47A09723.7020000@gandalf.sssup.it> <20080130164631.7de4f6bd@dhcp-252-066.norway.atmel.com> <47A12A2E.5040309@gandalf.sssup.it> Organization: Atmel Norway X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.5; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1501 Lines: 39 On Thu, 31 Jan 2008 02:53:50 +0100 michael wrote: > The overrun still remain. An lrz receive session is impossible using > full preemption. I will try the dma patch too and test in iso mode for > smart card. Hmm. Seems to work reasonably well on a non-rt kernel -- I get quite a few overruns, but nothing more than the Zmodem protocol can handle. It seems to be very sensitive to network traffic though...could it have something to do with softirq scheduling? Could you try the patch below and see if you can trigger the error message? Haavard diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index 477950f..c61fcc3 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -337,9 +337,12 @@ atmel_buffer_rx_char(struct uart_port *port, unsigned int status, struct circ_buf *ring = &atmel_port->rx_ring; struct atmel_uart_char *c; - if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE)) + if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE)) { + dev_err(port->dev, "RX ring buffer full, dropping data\n"); + /* Buffer overflow, ignore char */ return; + } c = &((struct atmel_uart_char *)ring->buf)[ring->head]; c->status = status; -- 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/