Messages in this thread Patch in this message |  | | From | Johan Hovold <> | | Subject | [PATCH 7/8] i2c: core: clean up bus id allocation | | Date | Tue, 5 May 2026 16:25:46 +0200 |
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Clean up bus id allocation by using a common helper and deferring it until it is needed during adapter registration.
Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/i2c/i2c-core-base.c | 86 ++++++++++++++++++------------------- 1 file changed, 42 insertions(+), 44 deletions(-)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 6209c5587e99..27cd9ca0ae81 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1517,23 +1517,48 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) } EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); +static int i2c_allocate_adapter_id(struct i2c_adapter *adap) +{ + int id, start, end; + + if (adap->nr == -1) { + start = __i2c_first_dynamic_bus_num; + end = 0; + } else { + start = adap->nr; + end = adap->nr + 1; + } + + mutex_lock(&core_lock); + id = idr_alloc(&i2c_adapter_idr, NULL, start, end, GFP_KERNEL); + mutex_unlock(&core_lock); + if (id < 0) { + if (adap->nr != -1 && id == -ENOSPC) + id = -EBUSY; + pr_err("adapter '%s': failed to allocate id: %d\n", adap->name, id); + return id; + } + + adap->nr = id; + + return 0; +} + static int i2c_register_adapter(struct i2c_adapter *adap) { - int res = -EINVAL; + int res; /* Can't register until after driver model init */ - if (WARN_ON(!is_registered)) { - res = -EAGAIN; - goto out_list; - } + if (WARN_ON(!is_registered)) + return -EAGAIN; /* Sanity checks */ if (WARN(!adap->name[0], "i2c adapter has no name")) - goto out_list; + return -EINVAL; if (!adap->algo) { pr_err("adapter '%s': no algo supplied!\n", adap->name); - goto out_list; + return -EINVAL; } if (!adap->lock_ops) @@ -1554,9 +1579,13 @@ static int i2c_register_adapter(struct i2c_adapter *adap) if (res) { pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", adap->name, res); - goto out_list; + return res; } + res = i2c_allocate_adapter_id(adap); + if (res) + return res; + dev_set_name(&adap->dev, "i2c-%d", adap->nr); adap->dev.bus = &i2c_bus_type; adap->dev.type = &i2c_adapter_type; @@ -1618,31 +1647,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap) init_completion(&adap->dev_released); put_device(&adap->dev); wait_for_completion(&adap->dev_released); -out_list: - mutex_lock(&core_lock); - idr_remove(&i2c_adapter_idr, adap->nr); - mutex_unlock(&core_lock); - return res; -} - -/** - * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 - * @adap: the adapter to register (with adap->nr initialized) - * Context: can sleep - * - * See i2c_add_numbered_adapter() for details. - */ -static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) -{ - int id; mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, NULL, adap->nr, adap->nr + 1, GFP_KERNEL); + idr_remove(&i2c_adapter_idr, adap->nr); mutex_unlock(&core_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; - return i2c_register_adapter(adap); + return res; } /** @@ -1665,17 +1675,8 @@ int i2c_add_adapter(struct i2c_adapter *adapter) int id; id = of_alias_get_id(dev->of_node, "i2c"); - if (id >= 0) { - adapter->nr = id; - return __i2c_add_numbered_adapter(adapter); - } - - mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, NULL, - __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); - mutex_unlock(&core_lock); - if (WARN(id < 0, "couldn't get idr")) - return id; + if (id < 0) + id = -1; adapter->nr = id; @@ -1708,10 +1709,7 @@ EXPORT_SYMBOL(i2c_add_adapter); */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - if (adap->nr == -1) /* -1 means dynamically assign bus id */ - return i2c_add_adapter(adap); - - return __i2c_add_numbered_adapter(adap); + return i2c_register_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); -- 2.53.0
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