From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756848AbZBJXvn (ORCPT ); Tue, 10 Feb 2009 18:51:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753883AbZBJXv3 (ORCPT ); Tue, 10 Feb 2009 18:51:29 -0500 Received: from mail-ew0-f21.google.com ([209.85.219.21]:61592 "EHLO mail-ew0-f21.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753620AbZBJXv2 convert rfc822-to-8bit (ORCPT ); Tue, 10 Feb 2009 18:51:28 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=BCulZ1Bw9UMfw1xANFZWU/oKcBDVXB8Ji2kyMwjaTJABNVV+7FbFHzYvBZa206TNg8 vKmFD4vbPdxCs1E7Cl0N9rNC2Sa6IDrmup437mrJkHkNWROPSjR5tDdfBInC0o5iRPaq MBCV9VfBHFoGh392nrPeCTiMdGDR9BIlmcc7A= MIME-Version: 1.0 In-Reply-To: <499211D0.3090705@tremplin-utc.net> References: <1234309249-13672-1-git-send-email-giuseppe.bilotta@gmail.com> <499211D0.3090705@tremplin-utc.net> Date: Wed, 11 Feb 2009 00:51:25 +0100 Message-ID: Subject: Re: [PATCHv2] lis3lv02d: support both one- and two-byte sensors From: Giuseppe Bilotta To: =?ISO-8859-1?Q?=C9ric_Piel?= Cc: git@vger.kernel.org, Pavel Machek , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 11, 2009 at 12:46 AM, Éric Piel wrote: > Giuseppe Bilotta schreef: >> >> Sensors responding with 0x3B to WHO_AM_I only have one data register per >> direction, thus returning a signed byte from the position which is >> occupied by the MSB in sensors responding with 0x3A. >> >> We support both kind of sensors by checking for the sensor type on init >> and defining appropriate data-access routines and sensor limits (for the >> joystick) depending on what we find. >> >> Signed-off-by: Giuseppe Bilotta >> --- >> >> This is the other version of the patch, and it changes access to use the >> base address from the 8-bit, so the 16-bit routine is changed to access >> the PREVIOUS byte for the LSB. >> >> Choose whichever of the patches is deemed more correct 8-) >> >> Note that both patches are based off Linus tree, so I don't know how >> they cope with Pavel's "don't touch too much on init" one. I'll try to >> work out a patch on top of that too. > > Yes, great, and this one looks even better than v1 :-) And don't forget about the v3 for -mm ;-) > However I'm not sure about the conversion between s8 and s16: > >> +static s16 lis3lv02d_read_8(acpi_handle handle, int reg) >> +{ >> + u8 lo; >> + adev.read(handle, reg, &lo); >> + return *((s8*)(&lo)); >> +} > > Does it really extend the sign to 16 bits? I would have written it this way: > +static s16 lis3lv02d_read_8(acpi_handle handle, int reg) > +{ > + s8 lo; > + adev.read(handle, reg, &lo); > + return (s16)lo; > +} > Doesn't it work better? Well, the previous one works, but I admit it's horribly convoluted. I'll double check with this one and resubmit (I'll only resubmit the one based on Pavel's "don't touch anything on init" probably though, hope it's ok) -- Giuseppe "Oblomov" Bilotta