Re: [PATCH v3] stmmac: enable rx queues

[Kishan Sandeep <sandeepkishan108@gmail.com>]

On Wed, Dec 28, 2016 at 5:23 PM, Joao Pinto <Joao.Pinto@synopsys.com> wrote:
> Hello,
>
> Às 11:50 AM de 12/28/2016, Kishan Sandeep escreveu:
>> On Wed, Dec 28, 2016 at 4:45 PM, Joao Pinto <Joao.Pinto@synopsys.com> wrote:
>>
>>> When the hardware is synthesized with multiple queues, all queues are
>>> disabled for default. This patch adds the rx queues configuration.
>>> This patch was successfully tested in a Synopsys QoS Reference design.
>>>
>>> Signed-off-by: Joao Pinto <jpinto@synopsys.com>
>>> ---
>>> changes v2 -> v3 (Seraphin Bonnaffe):
>>> - GMAC_RX_QUEUE_CLEAR macro simplified
>>> changes v1 -> v2 (Niklas Cassel and Seraphin Bonnaffe):
>>> - Instead of using number of DMA channels, lets use number of queues
>>> - Create 2 flavors of RX queue enable Macros: AV and DCB (AV by default)
>>> - Make sure that the RX queue related bits are cleared before setting
>>> - Check if rx_queue_enable is available before executing
>>>
>>>  drivers/net/ethernet/stmicro/stmmac/common.h      |  5 +++++
>>>  drivers/net/ethernet/stmicro/stmmac/dwmac4.h      |  8 ++++++++
>>>  drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 12 ++++++++++++
>>>  drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c  |  5 +++++
>>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 22
>>> ++++++++++++++++++++++
>>>  5 files changed, 52 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h
>>> b/drivers/net/ethernet/stmicro/stmmac/common.h
>>> index b13a144..6c96291 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/common.h
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/common.h
>>> @@ -323,6 +323,9 @@ struct dma_features {
>>>         /* TX and RX number of channels */
>>>         unsigned int number_rx_channel;
>>>         unsigned int number_tx_channel;
>>> +       /* TX and RX number of queues */
>>> +       unsigned int number_rx_queues;
>>> +       unsigned int number_tx_queues;
>>>
>>
>> Looks like this variable is unused. Current driver is only supporting
>> single Tx channel/queue. ??  Is current driver not supporting
>> multichannel/multiqueue ?
>
> stmmac has a good base for multichannel / multiple queue support, but is only
> using 1 for now. My next task is to add complete multiple queues / channel to
> stmmac amd that is why number of tx queues is being available.
>
> Thanks!

I believe *number_tx_queues* variable can be added at the time support
we are providing.

One query is that what is the algorithm that we are following
currently in the driver if we enable multi Rx queues/DMA channels ?

Thanks!