Re: [PATCH net-next v2 02/15] idpf: add module register and probe functionality

["Tantilov, Emil S" <emil.s.tantilov@intel.com>]

On 4/12/2023 11:03 PM, Leon Romanovsky wrote:
> On Wed, Apr 12, 2023 at 04:10:18PM -0700, Tantilov, Emil S wrote:
>>
>>
>> On 4/11/2023 5:36 AM, Leon Romanovsky wrote:
>>> On Mon, Apr 10, 2023 at 06:13:41PM -0700, Pavan Kumar Linga wrote:
>>>> From: Phani Burra <phani.r.burra@intel.com>
>>>>
>>>> Add the required support to register IDPF PCI driver, as well as
>>>> probe and remove call backs. Enable the PCI device and request
>>>> the kernel to reserve the memory resources that will be used by the
>>>> driver. Finally map the BAR0 address space.
>>>>
>>>> PCI IDs table is intentionally left blank to prevent the kernel from
>>>> probing the device with the incomplete driver. It will be added
>>>> in the last patch of the series.
>>>>
>>>> Signed-off-by: Phani Burra <phani.r.burra@intel.com>
>>>> Co-developed-by: Alan Brady <alan.brady@intel.com>
>>>> Signed-off-by: Alan Brady <alan.brady@intel.com>
>>>> Co-developed-by: Madhu Chittim <madhu.chittim@intel.com>
>>>> Signed-off-by: Madhu Chittim <madhu.chittim@intel.com>
>>>> Co-developed-by: Shailendra Bhatnagar <shailendra.bhatnagar@intel.com>
>>>> Signed-off-by: Shailendra Bhatnagar <shailendra.bhatnagar@intel.com>
>>>> Co-developed-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
>>>> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
>>>> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
>>>> Reviewed-by: Willem de Bruijn <willemb@google.com>
>>>> ---
>>>>    drivers/net/ethernet/intel/Kconfig            | 11 +++
>>>>    drivers/net/ethernet/intel/Makefile           |  1 +
>>>>    drivers/net/ethernet/intel/idpf/Makefile      | 10 ++
>>>>    drivers/net/ethernet/intel/idpf/idpf.h        | 27 ++++++
>>>>    .../net/ethernet/intel/idpf/idpf_controlq.h   | 14 +++
>>>>    drivers/net/ethernet/intel/idpf/idpf_lib.c    | 96 +++++++++++++++++++
>>>>    drivers/net/ethernet/intel/idpf/idpf_main.c   | 70 ++++++++++++++
>>>>    7 files changed, 229 insertions(+)
>>>>    create mode 100644 drivers/net/ethernet/intel/idpf/Makefile
>>>>    create mode 100644 drivers/net/ethernet/intel/idpf/idpf.h
>>>>    create mode 100644 drivers/net/ethernet/intel/idpf/idpf_controlq.h
>>>>    create mode 100644 drivers/net/ethernet/intel/idpf/idpf_lib.c
>>>>    create mode 100644 drivers/net/ethernet/intel/idpf/idpf_main.c
>>>
>>> <...>
> 
> <...>
> 
>>>> +/**
>>>> + * idpf_probe - Device initialization routine
>>>> + * @pdev: PCI device information struct
>>>> + * @ent: entry in idpf_pci_tbl
>>>> + *
>>>> + * Returns 0 on success, negative on failure
>>>> + */
>>>> +static int idpf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>>>> +{
>>>> +	struct idpf_adapter *adapter;
>>>> +
>>>> +	adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
>>>
>>> Why devm_kzalloc() and not kzalloc?
>> It provides managed memory allocation on probe, which seems to be the
>> preferred method in that case.
> 
> I don't think so, as PCI probe/remove has very clear lifetime model and
> doesn't need garbage collection memory logic. In general, it is better
> to avoid devm_*() APIs as they hide error unwind flows.

We'll remove it in v3.

Thanks,
Emil

> Thanks