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Message-ID: <1465546913-4284-2-git-send-email-kishon@ti.com>
Date: Fri, 10 Jun 2016 13:51:52 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: <gregkh@...uxfoundation.org>
CC: <kishon@...com>, <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/2] phy: exynos-mipi-video: avoid uninitialized variable use
From: Arnd Bergmann <arnd@...db.de>
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@...db.de>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@...sung.com>
Fixes: 97a3042f7616 ("phy: exynos-mipi-video: Rewrite handling of phy registers")
Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
---
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
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