From 194684e596af4bdaebb424166d94a8aa528edfda Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Sun, 6 Dec 2009 17:06:22 +0100 Subject: i2c: Prevent priority inversion on top of bus lock Low priority thread holding the i2c bus mutex could block higher priority threads to access the bus resulting in unacceptable latencies. Change the mutex type to rt_mutex preventing priority inversion. Tested-by: Peter Ujfalusi Signed-off-by: Mika Kuoppala Signed-off-by: Jean Delvare --- include/linux/i2c.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 7b40cda57a70..52317fb5917e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -338,8 +338,7 @@ struct i2c_adapter { void *algo_data; /* data fields that are valid for all devices */ - u8 level; /* nesting level for lockdep */ - struct mutex bus_lock; + struct rt_mutex bus_lock; int timeout; /* in jiffies */ int retries; @@ -367,7 +366,7 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) */ static inline void i2c_lock_adapter(struct i2c_adapter *adapter) { - mutex_lock(&adapter->bus_lock); + rt_mutex_lock(&adapter->bus_lock); } /** @@ -376,7 +375,7 @@ static inline void i2c_lock_adapter(struct i2c_adapter *adapter) */ static inline void i2c_unlock_adapter(struct i2c_adapter *adapter) { - mutex_unlock(&adapter->bus_lock); + rt_mutex_unlock(&adapter->bus_lock); } /*flags for the client struct: */ -- cgit v1.2.2 From c7b25a9e96dc89954ae8d8f473f56fae62030f84 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sun, 6 Dec 2009 17:06:24 +0100 Subject: i2c: Drop probe, ignore and force module parameters The legacy probe and force module parameters are obsolete now, the same can be achieved using the new_device sysfs interface, which is both more flexible and cheaper (it is implemented by i2c-core rather than replicated in every driver module.) The legacy ignore module parameters can be dropped as well. Ignoring can be done by instantiating a "dummy" device at the problematic address. This is the first step of a huge cleanup to i2c-core's i2c_detect function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made use of them. Signed-off-by: Jean Delvare --- include/linux/i2c.h | 91 +---------------------------------------------------- 1 file changed, 1 insertion(+), 90 deletions(-) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 52317fb5917e..419ab546b266 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -110,7 +110,7 @@ extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, * @driver: Device driver model driver * @id_table: List of I2C devices supported by this driver * @detect: Callback for device detection - * @address_data: The I2C addresses to probe, ignore or force (for detect) + * @address_data: The I2C addresses to probe (for detect) * @clients: List of detected clients we created (for i2c-core use only) * * The driver.owner field should be set to the module owner of this driver. @@ -397,9 +397,6 @@ static inline void i2c_unlock_adapter(struct i2c_adapter *adapter) */ struct i2c_client_address_data { const unsigned short *normal_i2c; - const unsigned short *probe; - const unsigned short *ignore; - const unsigned short * const *forces; }; /* Internal numbers to terminate lists */ @@ -613,134 +610,48 @@ union i2c_smbus_data { module_param_array(var, short, &var##_num, 0); \ MODULE_PARM_DESC(var, desc) -#define I2C_CLIENT_MODULE_PARM_FORCE(name) \ -I2C_CLIENT_MODULE_PARM(force_##name, \ - "List of adapter,address pairs which are " \ - "unquestionably assumed to contain a `" \ - # name "' chip") - - #define I2C_CLIENT_INSMOD_COMMON \ -I2C_CLIENT_MODULE_PARM(probe, "List of adapter,address pairs to scan " \ - "additionally"); \ -I2C_CLIENT_MODULE_PARM(ignore, "List of adapter,address pairs not to " \ - "scan"); \ static const struct i2c_client_address_data addr_data = { \ .normal_i2c = normal_i2c, \ - .probe = probe, \ - .ignore = ignore, \ - .forces = forces, \ } -#define I2C_CLIENT_FORCE_TEXT \ - "List of adapter,address pairs to boldly assume to be present" - /* These are the ones you want to use in your own drivers. Pick the one which matches the number of devices the driver differenciates between. */ #define I2C_CLIENT_INSMOD \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -static const unsigned short * const forces[] = { force, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_1(chip1) \ enum chips { any_chip, chip1 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_2(chip1, chip2) \ enum chips { any_chip, chip1, chip2 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_3(chip1, chip2, chip3) \ enum chips { any_chip, chip1, chip2, chip3 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_4(chip1, chip2, chip3, chip4) \ enum chips { any_chip, chip1, chip2, chip3, chip4 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip4); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, \ - force_##chip4, NULL}; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_5(chip1, chip2, chip3, chip4, chip5) \ enum chips { any_chip, chip1, chip2, chip3, chip4, chip5 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip4); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip5); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, \ - force_##chip4, force_##chip5, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_6(chip1, chip2, chip3, chip4, chip5, chip6) \ enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip4); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip5); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip6); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, \ - force_##chip4, force_##chip5, force_##chip6, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_7(chip1, chip2, chip3, chip4, chip5, chip6, chip7) \ enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6, \ chip7 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip4); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip5); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip6); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip7); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, \ - force_##chip4, force_##chip5, force_##chip6, \ - force_##chip7, NULL }; \ I2C_CLIENT_INSMOD_COMMON #define I2C_CLIENT_INSMOD_8(chip1, chip2, chip3, chip4, chip5, chip6, chip7, chip8) \ enum chips { any_chip, chip1, chip2, chip3, chip4, chip5, chip6, \ chip7, chip8 }; \ -I2C_CLIENT_MODULE_PARM(force, I2C_CLIENT_FORCE_TEXT); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip1); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip2); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip3); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip4); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip5); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip6); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip7); \ -I2C_CLIENT_MODULE_PARM_FORCE(chip8); \ -static const unsigned short * const forces[] = { force, \ - force_##chip1, force_##chip2, force_##chip3, \ - force_##chip4, force_##chip5, force_##chip6, \ - force_##chip7, force_##chip8, NULL }; \ I2C_CLIENT_INSMOD_COMMON #endif /* __KERNEL__ */ #endif /* _LINUX_I2C_H */ -- cgit v1.2.2