Re: [PATCH v2 01/10] net/ngbe: fix Rx buffer size in configure register

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 2/14/2023 9:55 AM, Ferruh Yigit wrote:
> On 2/14/2023 8:15 AM, Jiawen Wu wrote:
>> On Thursday, February 9, 2023 5:00 PM, Jiawen Wu wrote:
>>> On Wednesday, February 8, 2023 6:28 PM, Ferruh Yigit wrote:
>>>> On 2/2/2023 9:21 AM, Jiawen Wu wrote:
>>>>> When buffer size is less than 1K, round down makes it 0, which is an
>>>>> error value.
>>>>>
>>>>> Fixes: 62fc35e63d0e ("net/ngbe: support Rx queue start/stop")
>>>>> Cc: stable@dpdk.org
>>>>>
>>>>> Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
>>>>> ---
>>>>>  drivers/net/ngbe/ngbe_rxtx.c | 5 ++++-
>>>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/net/ngbe/ngbe_rxtx.c
>>>>> b/drivers/net/ngbe/ngbe_rxtx.c index 9fd24fa444..9a646cb6a7 100644
>>>>> --- a/drivers/net/ngbe/ngbe_rxtx.c
>>>>> +++ b/drivers/net/ngbe/ngbe_rxtx.c
>>>>> @@ -2944,7 +2944,10 @@ ngbe_dev_rx_init(struct rte_eth_dev *dev)
>>>>>  		 */
>>>>>  		buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
>>>>>  			RTE_PKTMBUF_HEADROOM);
>>>>> -		buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
>>>>> +		if (buf_size < 1024)
>>>>> +			buf_size = ROUND_UP(buf_size, 0x1 << 10);
>>>>
>>>> Back to original problem statement in previous version, can't this
>>>> cause HW to receive packets exceeding the buffer size?
>>>>
>>>> If HW accepts buffer size in multiple of 1K, does this mean any buffer
>>>> size less than 1K is an error condition for this HW?
>>>>
>>>
>>> After rechecking the code, the minimum buffer size is limited to 1K by the
>>> txgbe/ngbe [1].
>>> I think v1 patch for txgbe is enough.
>>>
>>> [1]
>>> static int
>>> txgbe_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info) {
>>> 	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
>>> 	struct txgbe_hw *hw = TXGBE_DEV_HW(dev);
>>>
>>> 	dev_info->min_rx_bufsize = 1024;
>>>
>>>
>>>>> +		else
>>>>> +			buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
>>>>>  		srrctl |= NGBE_RXCFG_PKTLEN(buf_size);
>>>>>
>>>>>  		wr32(hw, NGBE_RXCFG(rxq->reg_idx), srrctl);
>>>>
>>>>
>>>
>>
>> Hi Ferruh,
>>
>> Is my proposal feasible or do I need to send v3 patch for it?
>>
>>
> 
> Sorry Jiawen, I missed your response.
> 
> Yes, you are right, 'dev_info->min_rx_bufsize' prevents user to set
> buffer size less than 1K, so change in V1 is good.
> 
> There were some other changes too, instead of getting this patch from
> v1, can you please send a new version with latest updates?

We can drop 1/10 and you have sent a v3 for 2/10, right?