From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752926AbcFJIYA (ORCPT ); Fri, 10 Jun 2016 04:24:00 -0400 Received: from bear.ext.ti.com ([198.47.19.11]:57157 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750888AbcFJIV7 (ORCPT ); Fri, 10 Jun 2016 04:21:59 -0400 From: Kishon Vijay Abraham I To: CC: , Subject: [PATCH 1/2] phy: exynos-mipi-video: avoid uninitialized variable use Date: Fri, 10 Jun 2016 13:51:52 +0530 Message-ID: <1465546913-4284-2-git-send-email-kishon@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1465546913-4284-1-git-send-email-kishon@ti.com> References: <1465546913-4284-1-git-send-email-kishon@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann A rework of the exynos-mipi-video driver caused a warning about the new __set_phy_state function potentially accessing a variable before its initialization: drivers/phy/phy-exynos-mipi-video.c: In function '__set_phy_state': drivers/phy/phy-exynos-mipi-video.c:238:13: error: 'val' may be used uninitialized in this function [-Werror=maybe-uninitialized] return val & data->resetn_val; ~~~~^~~~~~~~~~~~~~~~~~ drivers/phy/phy-exynos-mipi-video.c:235:6: note: 'val' was declared here u32 val; The failure scenario here is the offset passed into a the stub regmap_read() function that does not modify its output, however regmap_read() can also fail for other reasons, so adding error handling (in this case, returning zero from is_running) seems the best solution. Note that this warning showed up with the ARM s5pv210_defconfig, indicating that we most likely want to either enable CONFIG_REGMAP in that defconfig as well, or disable the phy-exynos-mipi-video driver. Signed-off-by: Arnd Bergmann Reviewed-by: Krzysztof Kozlowski Fixes: 97a3042f7616 ("phy: exynos-mipi-video: Rewrite handling of phy registers") Signed-off-by: Kishon Vijay Abraham I --- drivers/phy/phy-exynos-mipi-video.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/phy/phy-exynos-mipi-video.c b/drivers/phy/phy-exynos-mipi-video.c index cc093eb..8b851f7 100644 --- a/drivers/phy/phy-exynos-mipi-video.c +++ b/drivers/phy/phy-exynos-mipi-video.c @@ -233,8 +233,12 @@ static inline int __is_running(const struct exynos_mipi_phy_desc *data, struct exynos_mipi_video_phy *state) { u32 val; + int ret; + + ret = regmap_read(state->regmaps[data->resetn_map], data->resetn_reg, &val); + if (ret) + return 0; - regmap_read(state->regmaps[data->resetn_map], data->resetn_reg, &val); return val & data->resetn_val; } -- 1.7.9.5