Re: [PATCH 3/9] staging: fsl-mc: add device release callback

[Laurentiu Tudor]

On 02/03/2017 02:02 AM, Stuart Yoder wrote:
>
>> -----Original Message-----
>> From: upstream-release-bounces@xxxxxxxxxxxxxxxxxxx [mailto:upstream-release-
>> bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of laurentiu.tudor@xxxxxxx
>> Sent: Wednesday, February 01, 2017 5:43 AM
>> To: gregkh@xxxxxxxxxxxxxxxxxxx
>> Cc: devel@xxxxxxxxxxxxxxxxxxxx; arnd@xxxxxxxx; Ruxandra Ioana Radulescu <ruxandra.radulescu@xxxxxxx>;
>> Roy Pledge <roy.pledge@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; agraf@xxxxxxx; Catalin Horghidan
>> <catalin.horghidan@xxxxxxx>; Leo Li <leoyang.li@xxxxxxx>; Stuart Yoder <stuart.yoder@xxxxxxx>;
>> Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
>> Subject: [upstream-release] [PATCH 3/9] staging: fsl-mc: add device release callback
>>
>> From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
>>
>> When hot unplugging a mc-bus device the kernel displays
>> this pertinent message, followed by a stack dump:
>>      "Device 'foo.N' does not have a release() function,
>>       it is broken and must be fixed."
>> Add the required callback to fix.
>>
>> Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
>> ---
>>   drivers/staging/fsl-mc/bus/fsl-mc-bus.c | 17 +++++++++++++++++
>>   1 file changed, 17 insertions(+)
>>
>> diff --git a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c
>> index 7c6a43b..6601bde 100644
>> --- a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c
>> +++ b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c
>> @@ -419,6 +419,22 @@ bool fsl_mc_is_root_dprc(struct device *dev)
>>   	return dev == root_dprc_dev;
>>   }
>>
>> +static void fsl_mc_device_release(struct device *dev)
>> +{
>> +	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
>> +	struct fsl_mc_bus *mc_bus = NULL;
>> +
>> +	kfree(mc_dev->regions);
>> +
>> +	if (strcmp(mc_dev->obj_desc.type, "dprc") == 0)
>> +		mc_bus = to_fsl_mc_bus(mc_dev);
>> +
>> +	if (mc_bus)
>> +		devm_kfree(mc_dev->dev.parent, mc_bus);
>> +	else
>> +		kmem_cache_free(mc_dev_cache, mc_dev);
>> +}
>> +
>>   /**
>>    * Add a newly discovered fsl-mc device to be visible in Linux
>>    */
>> @@ -460,6 +476,7 @@ int fsl_mc_device_add(struct dprc_obj_desc *obj_desc,
>>   	device_initialize(&mc_dev->dev);
>>   	mc_dev->dev.parent = parent_dev;
>>   	mc_dev->dev.bus = &fsl_mc_bus_type;
>> +	mc_dev->dev.release = fsl_mc_device_release;
>>   	dev_set_name(&mc_dev->dev, "%s.%d", obj_desc->type, obj_desc->id);
>>
>>   	if (strcmp(obj_desc->type, "dprc") == 0) {
>> --
>
> With this patch applied, you still have this:
>
> void fsl_mc_device_remove(struct fsl_mc_device *mc_dev)
> {
>          struct fsl_mc_bus *mc_bus = NULL;
>
>          kfree(mc_dev->regions);
>
>          /*
>           * The device-specific remove callback will get invoked by device_del()
>           */
>          device_del(&mc_dev->dev);
>          put_device(&mc_dev->dev);
>
>          if (strcmp(mc_dev->obj_desc.type, "dprc") == 0)
>                  mc_bus = to_fsl_mc_bus(mc_dev);
>
>          if (mc_bus)
>                  devm_kfree(mc_dev->dev.parent, mc_bus);
>          else
>                  kmem_cache_free(mc_dev_cache, mc_dev);
> }
>
> ...i.e. you are doing the same thing in 2 places.  You
> need to remove the kfree/devm_kfree/ kmem_cache_free,
> here, no?
>

Right, thanks for spotting. I started working on a v2
of the series.

---
Best Regards, Laurentiu