From: Arnd Bergmann <arnd@arndb.de> To: Kishon Vijay Abraham I <kishon@ti.com> Cc: Arnd Bergmann <arnd@arndb.de>, Kukjin Kim <kgene@kernel.org>, Krzysztof Kozlowski <k.kozlowski@samsung.com>, Sylwester Nawrocki <s.nawrocki@samsung.com>, Marek Szyprowski <m.szyprowski@samsung.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Subject: [PATCH] phy: exynos-mipi-video: avoid uninitialized variable use Date: Wed, 11 May 2016 14:49:53 +0200 [thread overview] Message-ID: <1462971012-562097-1-git-send-email-arnd@arndb.de> (raw) 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 <arnd@arndb.de> Fixes: 97a3042f7616 ("phy: exynos-mipi-video: Rewrite handling of phy registers") --- 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 cc093ebfda94..8b851f718123 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; } -- 2.7.0
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] phy: exynos-mipi-video: avoid uninitialized variable use Date: Wed, 11 May 2016 14:49:53 +0200 [thread overview] Message-ID: <1462971012-562097-1-git-send-email-arnd@arndb.de> (raw) 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 <arnd@arndb.de> Fixes: 97a3042f7616 ("phy: exynos-mipi-video: Rewrite handling of phy registers") --- 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 cc093ebfda94..8b851f718123 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; } -- 2.7.0
next reply other threads:[~2016-05-11 12:50 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-05-11 12:49 Arnd Bergmann [this message] 2016-05-11 12:49 ` [PATCH] phy: exynos-mipi-video: avoid uninitialized variable use Arnd Bergmann 2016-05-11 18:51 ` Krzysztof Kozlowski 2016-05-11 18:51 ` Krzysztof Kozlowski 2016-05-25 18:54 ` Arnd Bergmann 2016-05-25 18:54 ` Arnd Bergmann 2016-05-26 5:59 ` Kishon Vijay Abraham I 2016-05-26 5:59 ` Kishon Vijay Abraham I 2016-05-26 5:59 ` Kishon Vijay Abraham I
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