From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-we0-f171.google.com ([74.125.82.171]:37892 "EHLO mail-we0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757463Ab3BAVDe (ORCPT ); Fri, 1 Feb 2013 16:03:34 -0500 Received: by mail-we0-f171.google.com with SMTP id u54so3381121wey.30 for ; Fri, 01 Feb 2013 13:03:32 -0800 (PST) Message-ID: <510C2DA2.7020000@googlemail.com> Date: Fri, 01 Feb 2013 21:03:30 +0000 From: Chris Clayton MIME-Version: 1.0 To: Devin Heitmueller CC: linux-media@vger.kernel.org Subject: Re: WinTV-HVR-1400: scandvb (and kaffeine) fails to find any channels References: <510A9A1E.9090801@googlemail.com> <510ADB2F.4080901@googlemail.com> <510AF800.2090607@googlemail.com> <510BACD5.2070406@googlemail.com> <510BCE2F.1070100@googlemail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Devin, On 02/01/13 14:19, Devin Heitmueller wrote: > On Fri, Feb 1, 2013 at 9:16 AM, Chris Clayton wrote: >> I've got some more diagnostics. I tuned on the 12c debugging in the cx23885 >> driver and ran the scan again. Surprisingly, the scan found 22 channels on a >> single frequency (that carries the BBC channels). I've attached two files - >> the output from dvbscan and the kernel log covering the loading of the >> drivers and running the scan. >> >> I'm no kernel guru, but is it possible that the root cause of the scan >> failures is a timing problem which is being partially offset by the time >> taken to produce all the debug output? > > w_scan does have some arguments that let you increase the timeout for > tuning. You may wish to see if that has any effect. Maybe the w_scan > timeout is just too short for that device. > Yes, I noticed that but even with the tuning timeout set at medium or longest, I doesn't find any channels. However, I've been following the debug messages through the code and ended up at drivers/media/pci/cx23885/cx23885-i2c.c. I've found that by amending I2C_WAIT_DELAY from 32 to 64, I get improved results from scanning. With that delay doubled, scandvb now finds 49 channels over 3 frequencies. That's with all debugging turned off, so no extra delays provided by the production of debug messages. I'll play around more tomorrow and update then. Chris > Devin >