[U-Boot] [PATCH v2 12/26] dm: core: Allow uclasses to specific the private data for a device's children

[Simon Glass]

On 22 January 2015 at 03:25, Masahiro Yamada <yamada.m at jp.panasonic.com> wrote:
> Hi Simon,
>
>
>
> Perhaps a typo in this subject, too
>
> dm: core: Allow uclasses to specific the private data for a device's children
>
> s/to specific/to specify/  ??
>
>
> On Mon, 19 Jan 2015 20:12:41 -0700
> Simon Glass <sjg at chromium.org> wrote:
>
>> In many cases the per-child private data for a device's children is defined
>> by the uclass rather than the individual driver. For example, a SPI bus
>> needs to store information about each of its children, but all SPI drivers
>> store the same information. It makes sense to allow the uclass to define
>> this data.
>>
>> If the driver provides a size value for its per-child private data, then use
>> it. Failng that, fall back to that provided by the uclass.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>
>> Changes in v2: None
>>
>>  drivers/core/device-remove.c |  4 ++++
>>  drivers/core/device.c        |  4 ++++
>>  include/dm/uclass.h          |  4 ++++
>>  test/dm/bus.c                | 31 +++++++++++++++++++++++++++++--
>>  4 files changed, 41 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c
>> index 56c358a..3a5f48d 100644
>> --- a/drivers/core/device-remove.c
>> +++ b/drivers/core/device-remove.c
>> @@ -126,6 +126,10 @@ void device_free(struct udevice *dev)
>>       }
>>       if (dev->parent) {
>>               size = dev->parent->driver->per_child_auto_alloc_size;
>> +             if (!size) {
>> +                     size = dev->parent->uclass->uc_drv->
>> +                                     per_child_auto_alloc_size;
>> +             }
>>               if (size) {
>>                       free(dev->parent_priv);
>>                       dev->parent_priv = NULL;
>
>
> Hmm, do we need to check the per_child_auto_alloc_size?
> Is it better and simpler to check dev->parent_priv like this?
>
>       if (dev->parent && !dev->parent_priv) {
>                free(dev->parent_priv);
>                dev->parent_priv = NULL;
>       }
>
> Or further more simpily
>
>       if (dev->parent) {
>                free(dev->parent_priv);
>                dev->parent_priv = NULL;
>       }
>
> When free() is given with NULL pointer, it returns without doing anything,
> I think.

It is possible that the driver will allocate this memory itself, so in
that case we should not free it. The driver is responsible for that.

- Simon