From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from saturn.adsl24.co.uk ([84.234.17.186]) by www.linuxtv.org with esmtp (Exim 4.63) (envelope-from ) id 1LCxsO-0001UU-8o for linux-dvb@linuxtv.org; Wed, 17 Dec 2008 15:59:53 +0100 Received: from [78.32.116.227] (helo=gateway.wc) by saturn.adsl24.co.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1LCxrn-0002zM-B9 for linux-dvb@linuxtv.org; Wed, 17 Dec 2008 14:59:15 +0000 Received: from [192.168.241.65] by gateway.wc with esmtp (Exim 4.60) (envelope-from ) id 1LCxrn-0005bx-Rq for linux-dvb@linuxtv.org; Wed, 17 Dec 2008 14:59:15 +0000 Message-ID: <494913C4.9060704@sager.me.uk> Date: Wed, 17 Dec 2008 14:59:16 +0000 From: John Sager MIME-Version: 1.0 To: LinuxTV-DVB Subject: [linux-dvb] pci_abort messages from cx88 driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: linux-dvb-bounces@linuxtv.org Errors-To: linux-dvb-bounces+mchehab=infradead.org@linuxtv.org List-ID: This seems to have cropped up sporadically on mailing lists and fora, with no real resolution indicated. I have just bought a Hauppauge WinTV-NOVA-HD-S2 card (recognised as HVR4000(Lite)) which exhibits this problem in my system. I'm running Mythbuntu 8.10 on a quad core Intel-based system - P35/ICH9 chipset - with the v4l-dvb drivers cloned on 16th December. I don't get the problem on first start-up, but if I change channels it starts to appear. However it does seem to stop sometimes on channel change. I suspect the problem is either some kind of race condition between the Intel & Conexant PCI controllers, or some kind of missed or wrong step in chip reconfiguration after a channel change. When this error occurs, the standard behaviour of the code in cx88-mpeg.c is to stop the DMA current transfer & then restart the queue. This drops data, leading to blocky visuals & sound glitches. As an experiment, I changed the test for general errors in cx8802_mpeg_irq() to ignore the pci_abort error (change 0x1f0100 to 0x170100), and this completely eliminates the dropped data problem. This suggests that the pci transfers complete properly and the pci_abort status is a spurious indication. I also fixed the mask in the test for cx88_print_irqbits() to stop these messages filling up the log (change ~0xff to ~0x800ff). It may be worth fixing this in the main code to hide the problem for unfortunate users of this & related cards until the real problem is found. Unfortunately I doubt I can help there as a detailed knowledge of the Conexant PCI interface device is probably required to pursue it. regards, John _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb