i2c: make i2c_bus_type const

Message ID 2023121942-jumble-unethical-3163@gregkh
State New
Headers
Series i2c: make i2c_bus_type const |

Commit Message

Greg KH Dec. 19, 2023, 3:22 p.m. UTC
  Now that the driver core can properly handle constant struct bus_type,
move the i2c_bus_type variable to be a constant structure as well, placing
it into read-only memory which can not be modified at runtime.

Note, the sound/soc/rockchip/rk3399_gru_sound.c also needed tweaking as
it decided to save off a pointer to a bus type for internal stuff, and
it was using the i2c_bus_type as well.

Cc: Wolfram Sang <wsa@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-i2c@vger.kernel.org
Cc: linux-sound@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/i2c/i2c-core-base.c           | 2 +-
 include/linux/i2c.h                   | 2 +-
 sound/soc/rockchip/rk3399_gru_sound.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
  

Comments

Mark Brown Dec. 19, 2023, 3:24 p.m. UTC | #1
On Tue, Dec 19, 2023 at 04:22:43PM +0100, Greg Kroah-Hartman wrote:
> Now that the driver core can properly handle constant struct bus_type,
> move the i2c_bus_type variable to be a constant structure as well, placing
> it into read-only memory which can not be modified at runtime.

Acked-by: Mark Brown <broonie@kernel.org>
  
Wolfram Sang Dec. 19, 2023, 9:01 p.m. UTC | #2
On Tue, Dec 19, 2023 at 04:22:43PM +0100, Greg Kroah-Hartman wrote:
> Now that the driver core can properly handle constant struct bus_type,
> move the i2c_bus_type variable to be a constant structure as well, placing
> it into read-only memory which can not be modified at runtime.
> 
> Note, the sound/soc/rockchip/rk3399_gru_sound.c also needed tweaking as
> it decided to save off a pointer to a bus type for internal stuff, and
> it was using the i2c_bus_type as well.
> 
> Cc: Wolfram Sang <wsa@kernel.org>
> Cc: Liam Girdwood <lgirdwood@gmail.com>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: Jaroslav Kysela <perex@perex.cz>
> Cc: Takashi Iwai <tiwai@suse.com>
> Cc: Heiko Stuebner <heiko@sntech.de>
> Cc: linux-i2c@vger.kernel.org
> Cc: linux-sound@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-rockchip@lists.infradead.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Applied to for-next, thanks!
  

Patch

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index eac90a3cf61a..24c6e1b52668 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -689,7 +689,7 @@  static struct attribute *i2c_dev_attrs[] = {
 };
 ATTRIBUTE_GROUPS(i2c_dev);
 
-struct bus_type i2c_bus_type = {
+const struct bus_type i2c_bus_type = {
 	.name		= "i2c",
 	.match		= i2c_device_match,
 	.probe		= i2c_device_probe,
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 0dae9db27538..180462d1a373 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -23,7 +23,7 @@ 
 #include <linux/swab.h>		/* for swab16 */
 #include <uapi/linux/i2c.h>
 
-extern struct bus_type i2c_bus_type;
+extern const struct bus_type i2c_bus_type;
 extern struct device_type i2c_adapter_type;
 extern struct device_type i2c_client_type;
 
diff --git a/sound/soc/rockchip/rk3399_gru_sound.c b/sound/soc/rockchip/rk3399_gru_sound.c
index 1a504ebd3a0e..6c89c7331229 100644
--- a/sound/soc/rockchip/rk3399_gru_sound.c
+++ b/sound/soc/rockchip/rk3399_gru_sound.c
@@ -446,7 +446,7 @@  static const struct rockchip_sound_route rockchip_routes[] = {
 
 struct dailink_match_data {
 	const char *compatible;
-	struct bus_type *bus_type;
+	const struct bus_type *bus_type;
 };
 
 static const struct dailink_match_data dailink_match[] = {