[v2] i2c: convert to idr_alloc()
diff mbox

Message ID 20130207165547.GO2875@htj.dyndns.org
State Awaiting Upstream
Headers show

Commit Message

Tejun Heo Feb. 7, 2013, 4:55 p.m. UTC
Convert to the much saner new idr interface.

Only compile tested.

v2: The original conversion accidentally dropped a call to
    i2c_register_adapter() in i2c_add_numbered_adapter() leaving @adap
    uninitialized and unregistered.  Reported by Mark Brown.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: linux-i2c@vger.kernel.org
---
Heh, this is embarrassing.  I got too focused on the id allocation
itself and missed moving i2c_register_adapter() call.

I think this should fix the problem you're seeing.  Can you please
test this?

Thank you.

 drivers/i2c/i2c-core.c |   43 ++++++++++---------------------------------
 1 file changed, 10 insertions(+), 33 deletions(-)

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Comments

Mark Brown Feb. 7, 2013, 6:52 p.m. UTC | #1
On Thu, Feb 07, 2013 at 08:55:47AM -0800, Tejun Heo wrote:

> Heh, this is embarrassing.  I got too focused on the id allocation
> itself and missed moving i2c_register_adapter() call.

> I think this should fix the problem you're seeing.  Can you please
> test this?

Oops :) I'll test this tomorrow, out of time for today.
Mark Brown Feb. 8, 2013, 12:10 p.m. UTC | #2
On Thu, Feb 07, 2013 at 08:55:47AM -0800, Tejun Heo wrote:
> Convert to the much saner new idr interface.
> 
> Only compile tested.

Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Thanks!
Wolfram Sang Feb. 10, 2013, 11:47 a.m. UTC | #3
Hi,

thanks for doing this cleanup series. Looks very worthwhile!

> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -935,25 +935,16 @@ out_list:
>   */
>  int i2c_add_adapter(struct i2c_adapter *adapter)
>  {
> -	int	id, res = 0;
> -
> -retry:
> -	if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
> -		return -ENOMEM;
> +	int res;

I'd vote for using 'id' as the variable name here. Feels more logical to
me and you are using 'id' in the other block, too.

> @@ -984,33 +975,19 @@ EXPORT_SYMBOL(i2c_add_adapter);
>  int i2c_add_numbered_adapter(struct i2c_adapter *adap)
>  {
>  	int	id;
> -	int	status;
>  
>  	if (adap->nr == -1) /* -1 means dynamically assign bus id */
>  		return i2c_add_adapter(adap);
>  	if (adap->nr & ~MAX_IDR_MASK)
>  		return -EINVAL;
>  
> -retry:
> -	if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
> -		return -ENOMEM;
> -
>  	mutex_lock(&core_lock);
> -	/* "above" here means "above or equal to", sigh;
> -	 * we need the "equal to" result to force the result
> -	 */
> -	status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
> -	if (status == 0 && id != adap->nr) {
> -		status = -EBUSY;
> -		idr_remove(&i2c_adapter_idr, id);
> -	}
> +	id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1,
> +		       GFP_KERNEL);
>  	mutex_unlock(&core_lock);
> -	if (status == -EAGAIN)
> -		goto retry;
> -
> -	if (status == 0)
> -		status = i2c_register_adapter(adap);
> -	return status;
> +	if (id < 0)
> +		return id == -ENOSPC ? -EBUSY : id;
> +	return i2c_register_adapter(adap);

Add an empty line before the return statement?

Thanks,

   Wolfram

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Patch
diff mbox

--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -935,25 +935,16 @@  out_list:
  */
 int i2c_add_adapter(struct i2c_adapter *adapter)
 {
-	int	id, res = 0;
-
-retry:
-	if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
-		return -ENOMEM;
+	int res;
 
 	mutex_lock(&core_lock);
-	/* "above" here means "above or equal to", sigh */
-	res = idr_get_new_above(&i2c_adapter_idr, adapter,
-				__i2c_first_dynamic_bus_num, &id);
+	res = idr_alloc(&i2c_adapter_idr, adapter,
+			__i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
 	mutex_unlock(&core_lock);
-
-	if (res < 0) {
-		if (res == -EAGAIN)
-			goto retry;
+	if (res < 0)
 		return res;
-	}
 
-	adapter->nr = id;
+	adapter->nr = res;
 	return i2c_register_adapter(adapter);
 }
 EXPORT_SYMBOL(i2c_add_adapter);
@@ -984,33 +975,19 @@  EXPORT_SYMBOL(i2c_add_adapter);
 int i2c_add_numbered_adapter(struct i2c_adapter *adap)
 {
 	int	id;
-	int	status;
 
 	if (adap->nr == -1) /* -1 means dynamically assign bus id */
 		return i2c_add_adapter(adap);
 	if (adap->nr & ~MAX_IDR_MASK)
 		return -EINVAL;
 
-retry:
-	if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
-		return -ENOMEM;
-
 	mutex_lock(&core_lock);
-	/* "above" here means "above or equal to", sigh;
-	 * we need the "equal to" result to force the result
-	 */
-	status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
-	if (status == 0 && id != adap->nr) {
-		status = -EBUSY;
-		idr_remove(&i2c_adapter_idr, id);
-	}
+	id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1,
+		       GFP_KERNEL);
 	mutex_unlock(&core_lock);
-	if (status == -EAGAIN)
-		goto retry;
-
-	if (status == 0)
-		status = i2c_register_adapter(adap);
-	return status;
+	if (id < 0)
+		return id == -ENOSPC ? -EBUSY : id;
+	return i2c_register_adapter(adap);
 }
 EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);