On Thu, Aug 25, 2016 at 11:07:01PM +0200, Peter Rosin wrote:

This makes it trivial to constify them, so do that.

Signed-off-by: Peter Rosin peda@axentia.se

Acked-by: Daniel Vetter daniel.vetter@ffwll.ch

Feel free to merge through i2c tree. -Daniel

---

drivers/gpu/drm/drm_dp_helper.c | 10 +++++++--- drivers/i2c/i2c-core.c | 13 ++++++++----- drivers/i2c/i2c-mux.c | 25 ++++++++++++++++--------- include/linux/i2c.h | 25 ++++++++++++++++++------- 4 files changed, 49 insertions(+), 24 deletions(-)

Changes since v1:

• Also fix the user in drivers/gpu (only compile-tested, but it's simple enough...)

This takes care of the 0-day splat reported in: http://marc.info/?l=linux-i2c&m=147215193023544&w=2

Cheers, Peter

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index eae5ef963cb7..2bd064493ae7 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -790,6 +790,12 @@ static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags) mutex_unlock(&i2c_to_aux(i2c)->hw_mutex); }

+static const struct i2c_lock_operations drm_dp_i2c_lock_ops = {

• .lock_bus = lock_bus,
• .trylock_bus = trylock_bus,
• .unlock_bus = unlock_bus,

+};

/**

• drm_dp_aux_init() - minimally initialise an aux channel
• @aux: DisplayPort AUX channel

@@ -807,9 +813,7 @@ void drm_dp_aux_init(struct drm_dp_aux *aux) aux->ddc.algo_data = aux; aux->ddc.retries = 3;

• aux->ddc.lock_bus = lock_bus;
• aux->ddc.trylock_bus = trylock_bus;
• aux->ddc.unlock_bus = unlock_bus;

• aux->ddc.lock_ops = &drm_dp_i2c_lock_ops;

} EXPORT_SYMBOL(drm_dp_aux_init);

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 56e50ca905ba..0bdda24a10b2 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1691,6 +1691,12 @@ static int __process_new_adapter(struct device_driver *d, void *data) return i2c_do_add_adapter(to_i2c_driver(d), data); }

+static const struct i2c_lock_operations i2c_adapter_lock_ops = {

• .lock_bus = i2c_adapter_lock_bus,
• .trylock_bus = i2c_adapter_trylock_bus,
• .unlock_bus = i2c_adapter_unlock_bus,

+};

static int i2c_register_adapter(struct i2c_adapter *adap) { int res = -EINVAL; @@ -1710,11 +1716,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap) goto out_list; }

• if (!adap->lock_bus) {

• adap->lock_bus = i2c_adapter_lock_bus;
  

• adap->trylock_bus = i2c_adapter_trylock_bus;
  

• adap->unlock_bus = i2c_adapter_unlock_bus;
  

• }

• if (!adap->lock_ops)

• adap->lock_ops = &i2c_adapter_lock_ops;
  
  

  rt_mutex_init(&adap->bus_lock); rt_mutex_init(&adap->mux_lock);

diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 764f195795e4..14741ff31041 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -263,6 +263,18 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, } EXPORT_SYMBOL_GPL(i2c_mux_alloc);

+static const struct i2c_lock_operations i2c_mux_lock_ops = {

• .lock_bus = i2c_mux_lock_bus,
• .trylock_bus = i2c_mux_trylock_bus,
• .unlock_bus = i2c_mux_unlock_bus,

+};

+static const struct i2c_lock_operations i2c_parent_lock_ops = {

• .lock_bus = i2c_parent_lock_bus,
• .trylock_bus = i2c_parent_trylock_bus,
• .unlock_bus = i2c_parent_unlock_bus,

+};

int i2c_mux_add_adapter(struct i2c_mux_core *muxc, u32 force_nr, u32 chan_id, unsigned int class) @@ -312,15 +324,10 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, priv->adap.retries = parent->retries; priv->adap.timeout = parent->timeout; priv->adap.quirks = parent->quirks;

• if (muxc->mux_locked) {

• priv->adap.lock_bus = i2c_mux_lock_bus;
  

• priv->adap.trylock_bus = i2c_mux_trylock_bus;
  

• priv->adap.unlock_bus = i2c_mux_unlock_bus;
  

• } else {

• priv->adap.lock_bus = i2c_parent_lock_bus;
  

• priv->adap.trylock_bus = i2c_parent_trylock_bus;
  

• priv->adap.unlock_bus = i2c_parent_unlock_bus;
  

• }

• if (muxc->mux_locked)

• priv->adap.lock_ops = &i2c_mux_lock_ops;
  

• else

• priv->adap.lock_ops = &i2c_parent_lock_ops;
  
  

  /* Sanity check on class */ if (i2c_mux_parent_classes(parent) & class)

diff --git a/include/linux/i2c.h b/include/linux/i2c.h index c1f60a345db7..616f67635734 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -427,6 +427,20 @@ struct i2c_algorithm { };

/**

• • struct i2c_lock_operations - represent I2C locking operations
• • @lock_bus: Get exclusive access to an I2C bus segment
• • @trylock_bus: Try to get exclusive access to an I2C bus segment
• • @unlock_bus: Release exclusive access to an I2C bus segment
• • The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
• */

+struct i2c_lock_operations {

• void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
• int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
• void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);

+};

+/**

• struct i2c_timings - I2C timing information
• @bus_freq_hz: the bus frequency in Hz
• @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification

@@ -536,6 +550,7 @@ struct i2c_adapter { void *algo_data;

/* data fields that are valid for all devices */

• const struct i2c_lock_operations *lock_ops; struct rt_mutex bus_lock; struct rt_mutex mux_lock;

@@ -552,10 +567,6 @@ struct i2c_adapter {

struct i2c_bus_recovery_info *bus_recovery_info; const struct i2c_adapter_quirks *quirks;

• void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
• int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
• void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);

}; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)

@@ -597,7 +608,7 @@ int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); static inline void i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) {

• adapter->lock_bus(adapter, flags);

• adapter->lock_ops->lock_bus(adapter, flags);

}

/** @@ -611,7 +622,7 @@ i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) static inline int i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) {

• return adapter->trylock_bus(adapter, flags);

• return adapter->lock_ops->trylock_bus(adapter, flags);

}

/** @@ -623,7 +634,7 @@ i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) static inline void i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) {

• adapter->unlock_bus(adapter, flags);

• adapter->lock_ops->unlock_bus(adapter, flags);

}

static inline void

2.1.4

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