From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.bredband2.com ([83.219.192.166]:46534 "EHLO smtp.bredband2.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbaLFO1p (ORCPT ); Sat, 6 Dec 2014 09:27:45 -0500 Message-ID: <54831255.6080800@southpole.se> Date: Sat, 06 Dec 2014 15:27:33 +0100 From: Benjamin Larsson MIME-Version: 1.0 To: Antti Palosaari CC: Linux Media Mailing List Subject: Re: [PATCH 1/3] rtl28xxu: lower the rc poll time to mitigate i2c transfer errors References: <1417825533-13081-1-git-send-email-benjamin@southpole.se> <5482FABE.3050004@iki.fi> In-Reply-To: <5482FABE.3050004@iki.fi> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 12/06/2014 01:46 PM, Antti Palosaari wrote: > Moikka! > I am very surprised about that patch, especially because it > *increases* polling interval from 400ms to 200ms. For me it has been > always worked rather well, but now I suspect it could be due to I > disable always remote controller... I have to test that. > > regards > Antti I noticed that I got more retry errors when I removed the poll. So when I tried lowering the interval time the errors totally disappeared for me. Exactly how it works is unclear to me but I guess that the rc poll triggers something in the chip to mitigate some overflow in the i2c transmit buffer. This workaround also suggest that the i2c bus actually is ok and not the cause for the errors. Anyway please test and if this is an acceptable solution then there might also be some check that this poll is active and set to 200 at all times for this card. At least when the card is set in dvb mode, for sdr mode this might not be an issue. MvH Benjamin Larsson