Re: [EXT] Re: [net PATCH 1/5] octeontx2-af: Adjust Tx credits when MCS external bypass is disabled

[Wojciech Drewek]

On 23.11.2023 13:34, Geethasowjanya Akula wrote:
> 
> 
>> -----Original Message-----
>> From: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>
>> Sent: Thursday, November 23, 2023 4:15 PM
>> To: Geethasowjanya Akula <gakula@xxxxxxxxxxx>; netdev@xxxxxxxxxxxxxxx;
>> linux-kernel@xxxxxxxxxxxxxxx
>> Cc: kuba@xxxxxxxxxx; davem@xxxxxxxxxxxxx; pabeni@xxxxxxxxxx;
>> edumazet@xxxxxxxxxx; Sunil Kovvuri Goutham <sgoutham@xxxxxxxxxxx>;
>> Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxxx>; Hariprasad Kelam
>> <hkelam@xxxxxxxxxxx>
>> Subject: [EXT] Re: [net PATCH 1/5] octeontx2-af: Adjust Tx credits when MCS
>> external bypass is disabled
>>
>> External Email
>>
>> ----------------------------------------------------------------------
>>
>>
>> On 23.11.2023 06:59, Geetha sowjanya wrote:
>>> From: Nithin Dabilpuram <ndabilpuram@xxxxxxxxxxx>
>>>
>>> When MCS external bypass is disabled, MCS returns additional
>>> 2 credits(32B) for every packet Tx'ed on LMAC. To account for these
>>> extra credits, NIX_AF_TX_LINKX_NORM_CREDIT.CC_MCS_CNT
>>> needs to be configured as otherwise NIX Tx credits would overflow and
>>> will never be returned to idle state credit count causing issues with
>>> credit control and MTU change.
>>>
>>> This patch fixes the same by configuring CC_MCS_CNT at probe time for
>>> MCS enabled SoC's
>>>
>>> Fixes: bd69476e86fc ("octeontx2-af: cn10k: mcs: Install a default TCAM
>>> for normal traffic")
>>> Signed-off-by: Nithin Dabilpuram <ndabilpuram@xxxxxxxxxxx>
>>> Signed-off-by: Geetha sowjanya <gakula@xxxxxxxxxxx>
>>> Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxxx>
>>> ---
>>>  drivers/net/ethernet/marvell/octeontx2/af/mcs.c     | 12 ++++++++++++
>>>  drivers/net/ethernet/marvell/octeontx2/af/mcs.h     |  2 ++
>>>  drivers/net/ethernet/marvell/octeontx2/af/rvu.h     |  1 +
>>>  drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c |  8 ++++++++
>>>  4 files changed, 23 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/mcs.c
>>> b/drivers/net/ethernet/marvell/octeontx2/af/mcs.c
>>> index c43f19dfbd74..d6effbe46208 100644
>>> --- a/drivers/net/ethernet/marvell/octeontx2/af/mcs.c
>>> +++ b/drivers/net/ethernet/marvell/octeontx2/af/mcs.c
>>> @@ -1219,6 +1219,17 @@ struct mcs *mcs_get_pdata(int mcs_id)
>>>  	return NULL;
>>>  }
>>>
>>> +bool is_mcs_bypass(int mcs_id)
>>> +{
>>> +	struct mcs *mcs_dev;
>>> +
>>> +	list_for_each_entry(mcs_dev, &mcs_list, mcs_list) {
>>> +		if (mcs_dev->mcs_id == mcs_id)
>>> +			return mcs_dev->bypass;
>>> +	}
>>> +	return true;
>>
>> If there is no mcs dev with the given id it means it is bypassed?
> Yes.

Makes sense
Reviewed-by: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>

>>
>>> +}
>>> +
>>>  void mcs_set_port_cfg(struct mcs *mcs, struct mcs_port_cfg_set_req
>>> *req)  {
>>>  	u64 val = 0;
>>> @@ -1447,6 +1458,7 @@ static void mcs_set_external_bypass(struct mcs
>> *mcs, u8 bypass)
>>>  	else
>>>  		val &= ~BIT_ULL(6);
>>>  	mcs_reg_write(mcs, MCSX_MIL_GLOBAL, val);
>>> +	mcs->bypass = bypass;
>>>  }
>>>
>>>  static void mcs_global_cfg(struct mcs *mcs)
>>
>>
>> <...>