From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752806Ab0J0RLk (ORCPT ); Wed, 27 Oct 2010 13:11:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32890 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752463Ab0J0RLj (ORCPT ); Wed, 27 Oct 2010 13:11:39 -0400 Message-ID: <4CC85D34.7010603@redhat.com> Date: Wed, 27 Oct 2010 15:11:16 -0200 From: Mauro Carvalho Chehab User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100827 Red Hat/3.1.3-1.el6 Lightning/1.0b2 Thunderbird/3.1.3 MIME-Version: 1.0 To: Antti Palosaari CC: Jiri Slaby , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mm-commits@vger.kernel.org, Greg KH , USB list Subject: Re: DVB: af9015 defunct [was: mmotm 2010-10-20-15-01 uploaded] References: <201010202233.o9KMXNoL008303@imap1.linux-foundation.org> <4CC07DB4.20205@gmail.com> <4CC1577F.9060207@gmail.com> <4CC19804.1080109@redhat.com> <4CC19A6E.8010909@gmail.com> <4CC84F60.7000409@redhat.com> <4CC85633.6030707@iki.fi> In-Reply-To: <4CC85633.6030707@iki.fi> Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em 27-10-2010 14:41, Antti Palosaari escreveu: > On 10/27/2010 07:12 PM, Mauro Carvalho Chehab wrote: >> int tda18271_write_regs(struct dvb_frontend *fe, int idx, int len) >> { >> ... >> switch (priv->small_i2c) { >> case TDA18271_03_BYTE_CHUNK_INIT: >> max = 3; >> break; >> case TDA18271_08_BYTE_CHUNK_INIT: >> max = 8; >> break; >> case TDA18271_16_BYTE_CHUNK_INIT: >> max = 16; >> break; >> case TDA18271_39_BYTE_CHUNK_INIT: >> default: >> max = 39; >> } >> >> >> with small_i2c = 1, the driver will not restrict the maximum length size. >> >> It's weird that the patch didn't fix it. Are you sure that reverting this >> patch is enough to make the driver work? >> >> Please test this one. >> >> It will properly log the size of the message the driver tried to use, and will >> reduce the max number of bytes per I2C transfer to 8. > > All in all, this small_i2c was added (Michael Krufky and I) when this tuner was taken in use with af9015 and it was 16 bytes initially. I think those other chunks are added later. Yeah, another change added a max restriction of 8. > AF9015 I2C adapter can write 21 bytes at once. > Correct solution is to add option which splits writes as wanted (like option .i2c_wr_max) to the TDA18271. I have no HW to test. Changing to 21 won't change anything in practice, as it will still use 3 URB's for transferring data. Only at setup, it needs to write values on more than 16 registers. The current way that .small_i2c is defined is like that: it specifies the maximum amount of data that can be transferred. I won't object to change it from an enum into an integer, although I would do it only if we need to touch on that code for another reason. Cheers, Mauro