[PATCH] i2c: bcm2835: Make sure clk_init_data is fully initialized

[PATCH] i2c: bcm2835: Make sure clk_init_data is fully initialized

[Geert Uytterhoeven]

The clk_init_data structure contains several mutually-exclusive members
for different methods to specify the possible parents of a clock,
prompting drivers to initialize only the members they need.  However,
not initializing all members may cause subtle issues, which are only
exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is
enabled.

Make sure all members are fully initialized, to avoid such bugs, and to
prevent future breakage when converting drivers to a different method
for specifying the parents.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Compile-tested only.

Part One[1] fixed all cases that I identified to be real bugs, in
response to a crash I saw on BeagleBone Black.

This patch is the I2C subpart of Part Two, which fixes remaining cases
that are currently harmless.  These are still fragile, and may cause
future breakage when converting drivers to a different method for
specifying the parents.

[1] "[PATCH treewide 0/5] clk: Make sure clk_init_data is fully
     initialized (part 1)"
    https://lore.kernel.org/cover.1787165329.git.geert+renesas@glider.be

---
 drivers/i2c/busses/i2c-bcm2835.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index 0d7e2654a534e92a..b30f7e0e45f160c2 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -166,7 +166,7 @@ static struct clk *bcm2835_i2c_register_div(struct device *dev,
 					struct clk *mclk,
 					struct bcm2835_i2c_dev *i2c_dev)
 {
-	struct clk_init_data init;
+	struct clk_init_data init = {};
 	struct clk_bcm2835_i2c *priv;
 	char name[32];
 	const char *mclk_name;
-- 
2.43.0

Re: [PATCH] i2c: bcm2835: Make sure clk_init_data is fully initialized

[Brian Masney]

On Fri, Aug 21, 2026 at 12:03:30PM +0200, Geert Uytterhoeven wrote:
> The clk_init_data structure contains several mutually-exclusive members
> for different methods to specify the possible parents of a clock,
> prompting drivers to initialize only the members they need.  However,
> not initializing all members may cause subtle issues, which are only
> exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is
> enabled.
> 
> Make sure all members are fully initialized, to avoid such bugs, and to
> prevent future breakage when converting drivers to a different method
> for specifying the parents.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Brian Masney <bmasney@redhat.com>

Re: [PATCH] i2c: bcm2835: Make sure clk_init_data is fully initialized

[Florian Fainelli]

On 8/21/26 03:03, Geert Uytterhoeven wrote:
> The clk_init_data structure contains several mutually-exclusive members
> for different methods to specify the possible parents of a clock,
> prompting drivers to initialize only the members they need.  However,
> not initializing all members may cause subtle issues, which are only
> exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is
> enabled.
> 
> Make sure all members are fully initialized, to avoid such bugs, and to
> prevent future breakage when converting drivers to a different method
> for specifying the parents.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
-- 
Florian

Re: [PATCH] i2c: bcm2835: Make sure clk_init_data is fully initialized

[Andi Shyti]

Hi Geert,

On Fri, Aug 21, 2026 at 12:03:30PM +0200, Geert Uytterhoeven wrote:
> The clk_init_data structure contains several mutually-exclusive members
> for different methods to specify the possible parents of a clock,
> prompting drivers to initialize only the members they need.  However,
> not initializing all members may cause subtle issues, which are only
> exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is
> enabled.
> 
> Make sure all members are fully initialized, to avoid such bugs, and to
> prevent future breakage when converting drivers to a different method
> for specifying the parents.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

merged to i2c/i2c.

Thanks,
Andi