Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754678AbbGCIK6 (ORCPT ); Fri, 3 Jul 2015 04:10:58 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:37788 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754811AbbGCIKl (ORCPT ); Fri, 3 Jul 2015 04:10:41 -0400 Date: Fri, 3 Jul 2015 10:10:38 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Darren Hart Cc: Matthew Garrett , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, Gabriele Mazzotta Subject: Re: [PATCH 1/3] dell-laptop: Clear buffer before each SMBIOS call Message-ID: <20150703081038.GF1841@pali> References: <201507012004.45275@pali> <1435774101-12329-1-git-send-email-pali.rohar@gmail.com> <20150702004544.GD27795@vmdeb7> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20150702004544.GD27795@vmdeb7> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2953 Lines: 85 On Wednesday 01 July 2015 17:45:44 Darren Hart wrote: > On Wed, Jul 01, 2015 at 08:08:19PM +0200, Pali Rohár wrote: > > Make sure that before initializing SMBIOS call input buffer does not contain > > any garbage (e.g values from previous SMBIOS call). This fix problem with > > passing undefined/random parameters to SMBIOS functions. > > > > Signed-off-by: Pali Rohár > > --- > > drivers/platform/x86/dell-laptop.c | 11 ++++++++++- > > 1 file changed, 10 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c > > index 35758cb..6728487 100644 > > --- a/drivers/platform/x86/dell-laptop.c > > +++ b/drivers/platform/x86/dell-laptop.c > > @@ -310,10 +310,15 @@ static DEFINE_MUTEX(buffer_mutex); > > > > static int hwswitch_state; > > > > +static void clear_buffer(void) > > +{ > > + memset(buffer, 0, sizeof(struct calling_interface_buffer)); > > +} > > + > > static void get_buffer(void) > > { > > mutex_lock(&buffer_mutex); > > - memset(buffer, 0, sizeof(struct calling_interface_buffer)); > > + clear_buffer(); > > } > > > > static void release_buffer(void) > > @@ -557,6 +562,8 @@ static int dell_rfkill_set(void *data, bool blocked) > > !(buffer->output[1] & BIT(16))) > > disable = 1; > > > > + clear_buffer(); > > + > > buffer->input[0] = (1 | (radio<<8) | (disable << 16)); > > dell_send_request(buffer, 17, 11); > > > > @@ -571,6 +578,7 @@ static void dell_rfkill_update_sw_state(struct rfkill *rfkill, int radio, > > if (status & BIT(0)) { > > /* Has hw-switch, sync sw_state to BIOS */ > > int block = rfkill_blocked(rfkill); > > + clear_buffer(); > > buffer->input[0] = (1 | (radio << 8) | (block << 16)); > > dell_send_request(buffer, 17, 11); > > } else { > > @@ -774,6 +782,7 @@ static int __init dell_setup_rfkill(void) > > dell_send_request(buffer, 17, 11); > > status = buffer->output[1]; > > buffer->input[0] = 0x2; > > + clear_buffer(); > > dell_send_request(buffer, 17, 11); > > This clears the buffer after modifying input[0] and right before > dell_send_request... so you're sending a completely empty buffer? Is that > intentional here? I guess I would have expected the clear_buffer to be one line > earlier. > Yes, now I see. I split that one patch into tree and I checked that every one compiles fine and cumulative change of all patches is same... Because that part (sending 0x2) is deleted in patch 3/3 it missed in my eyes... I will fix these problems and sent patch series again. > > hwswitch_state = buffer->output[1]; > > release_buffer(); > > -- > > 1.7.9.5 > > > > > -- Pali Rohár pali.rohar@gmail.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/