From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH 1/3] dell-laptop: Clear buffer before each SMBIOS call Date: Wed, 1 Jul 2015 17:45:44 -0700 Message-ID: <20150702004544.GD27795@vmdeb7> References: <201507012004.45275@pali> <1435774101-12329-1-git-send-email-pali.rohar@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:40593 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753657AbbGBApu (ORCPT ); Wed, 1 Jul 2015 20:45:50 -0400 Content-Disposition: inline In-Reply-To: <1435774101-12329-1-git-send-email-pali.rohar@gmail.com> Sender: platform-driver-x86-owner@vger.kernel.org List-ID: To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Matthew Garrett , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, Gabriele Mazzotta On Wed, Jul 01, 2015 at 08:08:19PM +0200, Pali Roh=E1r 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. >=20 > Signed-off-by: Pali Roh=E1r > --- > drivers/platform/x86/dell-laptop.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x8= 6/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); > =20 > static int hwswitch_state; > =20 > +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(); > } > =20 > static void release_buffer(void) > @@ -557,6 +562,8 @@ static int dell_rfkill_set(void *data, bool block= ed) > !(buffer->output[1] & BIT(16))) > disable =3D 1; > =20 > + clear_buffer(); > + > buffer->input[0] =3D (1 | (radio<<8) | (disable << 16)); > dell_send_request(buffer, 17, 11); > =20 > @@ -571,6 +578,7 @@ static void dell_rfkill_update_sw_state(struct rf= kill *rfkill, int radio, > if (status & BIT(0)) { > /* Has hw-switch, sync sw_state to BIOS */ > int block =3D rfkill_blocked(rfkill); > + clear_buffer(); > buffer->input[0] =3D (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 =3D buffer->output[1]; > buffer->input[0] =3D 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 th= at intentional here? I guess I would have expected the clear_buffer to be = one line earlier. > hwswitch_state =3D buffer->output[1]; > release_buffer(); > --=20 > 1.7.9.5 >=20 >=20 --=20 Darren Hart Intel Open Source Technology Center