From ced53f6d12e497ba210a518e7e76178da987f932 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= Date: Mon, 6 Jul 2015 12:08:55 +0200 Subject: [PATCH] dell-laptop: Clear buffer before each SMBIOS call MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure that before initializing SMBIOS call, the input buffer does not contain any garbage (e.g. values from previous SMBIOS call). This fixes problems with passing undefined/random parameters to SMBIOS functions. Signed-off-by: Pali Rohár Signed-off-by: Darren Hart --- 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 ed317ccac4a2..85fbe7c247a4 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -311,10 +311,15 @@ 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) @@ -558,6 +563,8 @@ 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); @@ -572,6 +579,7 @@ 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) get_buffer(); dell_send_request(buffer, 17, 11); status = buffer->output[1]; + clear_buffer(); buffer->input[0] = 0x2; dell_send_request(buffer, 17, 11); hwswitch_state = buffer->output[1];