Hi,
On Sat, Jun 09, 2018 at 02:22:45PM +0200, Javier Martinez Canillas wrote:
> The struct clk_init_data init variable is declared in the isp_xclk_init()
> function so is an automatic variable allocated in the stack. But it's not
> explicitly zero-initialized, so some init fields are left uninitialized.
>
> This causes the data structure to have undefined values that may confuse
> the common clock framework when the clock is registered.
>
> For example, the uninitialized .flags field could have the CLK_IS_CRITICAL
> bit set, causing the framework to wrongly prepare the clk on registration.
> This leads to the isp_xclk_prepare() callback being called, which in turn
> calls to the omap3isp_get() function that increments the isp dev refcount.
>
> Since this omap3isp_get() call is unexpected, this leads to an unbalanced
> omap3isp_get() call that prevents the requested IRQ to be later enabled,
> due the refcount not being 0 when the correct omap3isp_get() call happens.
>
> Fixes: 9b28ee3c9122 ("[media] omap3isp: Use the common clock framework")
> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
good catch!
Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
-- Sebastian
>
> ---
>
> Changes in v2:
> - Correct some typos in the commit message.
>
> drivers/media/platform/omap3isp/isp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
> index f22cf351e3e..ae0ef8b241a 100644
> --- a/drivers/media/platform/omap3isp/isp.c
> +++ b/drivers/media/platform/omap3isp/isp.c
> @@ -300,7 +300,7 @@ static struct clk *isp_xclk_src_get(struct of_phandle_args *clkspec, void *data)
> static int isp_xclk_init(struct isp_device *isp)
> {
> struct device_node *np = isp->dev->of_node;
> - struct clk_init_data init;
> + struct clk_init_data init = { 0 };
> unsigned int i;
>
> for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i)
> --
> 2.17.1
>
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