From 06061dc63bff8d609bc8d64f5d3ef59d0a673b25 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 11 May 2016 14:49:53 +0200 Subject: [PATCH] phy: exynos-mipi-video: avoid uninitialized variable use 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; } -- 2.7.4