media: fimc: check return value of clk_enable in runtime_resume

In fimc_runtime_resume(), the return value of
clk_enable(fimc->clock[CLK_GATE]) was not checked. If enabling the clock
fails, subsequent register accesses (fimc_hw_reset() and capture/m2m
resume) may trigger a bus error or undefined behavior.

Fix this by checking the return value. If clk_enable() fails, return the
error immediately, preventing unsafe hardware access.

Signed-off-by: Zhaoyang Yu <2426767509@qq.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/samsung/exynos4-is/fimc-core.c b/drivers/media/platform/samsung/exynos4-is/fimc-core.c
index 2c9edd0a559b8560233ff81ec81906fc8855efa7..57e573949e54dfb6ed1d9e1dff656da0a7fc2f0b 100644 (file)
--- a/drivers/media/platform/samsung/exynos4-is/fimc-core.c
+++ b/drivers/media/platform/samsung/exynos4-is/fimc-core.c
@@ -1020,11 +1020,15 @@ err_sclk:
 static int fimc_runtime_resume(struct device *dev)
 {
        struct fimc_dev *fimc = dev_get_drvdata(dev);
+       int ret;
 
        dbg("fimc%d: state: 0x%lx", fimc->id, fimc->state);
 
        /* Enable clocks and perform basic initialization */
-       clk_enable(fimc->clock[CLK_GATE]);
+       ret = clk_enable(fimc->clock[CLK_GATE]);
+       if (ret)
+               return ret;
+
        fimc_hw_reset(fimc);
 
        /* Resume the capture or mem-to-mem device */