Re: [dpdk-dev] [PATCH v4] net/ice: simplify the use of DCF device reset

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Yu, DapengX <dapengx.yu@intel.com>
> Sent: Tuesday, October 26, 2021 4:44 PM
> To: Yang, Qiming <qiming.yang@intel.com>; Zhang, Qi Z
> <qi.z.zhang@intel.com>
> Cc: dev@dpdk.org; Yu, DapengX <dapengx.yu@intel.com>; stable@dpdk.org
> Subject: [PATCH v4] net/ice: simplify the use of DCF device reset
> 
> From: Dapeng Yu <dapengx.yu@intel.com>
> 
> After DCF is reset by PF, the DCF device un-initialization cannot function
> normally since the resource is already invalidated. So reset DCF twice is
> necessary, the first simplified reset re-initializes the AdminQ of DCF, only then
> second reset can clean the filters successfully.
> 
> This patch detects the reset flag, which is set by PF on DCF reset, if the flag is
> true, do DCF reset twice automatically.
> 
> Fixes: 1a86f4dbdf42 ("net/ice: support DCF device reset")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
> ---
> V2:
> * Ignore the returned error of dev_uninit when DCF is reset by PF
> V3:
> * Add a reset function to re-initialize AdminQ resource
> * Add a function to check the reset flag
> V4:
> * Remove redundant reset flag setting
> ---
>  drivers/net/ice/ice_dcf.c        |  2 ++
>  drivers/net/ice/ice_dcf_ethdev.c | 33 +++++++++++++++++++++++++++++++-
>  2 files changed, 34 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ice/ice_dcf.c b/drivers/net/ice/ice_dcf.c index
> 084f7a53db..366ff0a907 100644
> --- a/drivers/net/ice/ice_dcf.c
> +++ b/drivers/net/ice/ice_dcf.c
> @@ -593,6 +593,8 @@ ice_dcf_init_hw(struct rte_eth_dev *eth_dev, struct
> ice_dcf_hw *hw)
>  	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(eth_dev);
>  	int ret, size;
> 
> +	hw->resetting = false;
> +
>  	hw->avf.hw_addr = pci_dev->mem_resource[0].addr;
>  	hw->avf.back = hw;
> 
> diff --git a/drivers/net/ice/ice_dcf_ethdev.c b/drivers/net/ice/ice_dcf_ethdev.c
> index 7c71a48010..171b58a748 100644
> --- a/drivers/net/ice/ice_dcf_ethdev.c
> +++ b/drivers/net/ice/ice_dcf_ethdev.c
> @@ -1025,11 +1025,43 @@ ice_dcf_tm_ops_get(struct rte_eth_dev *dev
> __rte_unused,
>  	return 0;
>  }
> 
> +static inline void
> +ice_dcf_simple_reset(struct rte_eth_dev *eth_dev, struct ice_dcf_hw	

Better to rename the function to ice_dcf_reset_hw 

> +*hw) {
> +	ice_dcf_uninit_hw(eth_dev, hw);
> +	ice_dcf_init_hw(eth_dev, hw);
> +}
> +
> +/* Check if reset has been triggered by PF */ static inline bool
> +dcf_is_reset(struct rte_eth_dev *dev) {
> +	struct ice_dcf_adapter *ad = dev->data->dev_private;
> +	struct iavf_hw *hw = &ad->real_hw.avf;
> +
> +	return !(IAVF_READ_REG(hw, IAVF_VF_ARQLEN1) &
> +		 IAVF_VF_ARQLEN1_ARQENABLE_MASK);
> +}
> +
>  static int
>  ice_dcf_dev_reset(struct rte_eth_dev *dev)  {
> +	struct ice_dcf_adapter *ad = dev->data->dev_private;
> +	struct ice_dcf_hw *hw = &ad->real_hw;
>  	int ret;
> 
> +	if (dcf_is_reset(dev)) {
> +		if (!ad->real_hw.resetting)
> +			ad->real_hw.resetting = true;
> +		PMD_DRV_LOG(ERR, "The DCF has been reset by PF");
> +
> +		/*
> +		 * Do the simplified reset to make DCF get AdminQ resource.
> +		 * Then the next uninit/init can clean filters successfully.
> +		 */		

Can reword as below:

Simply reset hw to trigger an additional DCF enable/disable cycle which help to workaround
the issue that kernel driver may not clean up resource during previous reset.

> +		ice_dcf_simple_reset(dev, hw);
> +	}
> +
>  	ret = ice_dcf_dev_uninit(dev);
>  	if (ret)
>  		return ret;
> @@ -1072,7 +1104,6 @@ ice_dcf_dev_init(struct rte_eth_dev *eth_dev)  {
>  	struct ice_dcf_adapter *adapter = eth_dev->data->dev_private;
> 
> -	adapter->real_hw.resetting = false;
>  	eth_dev->dev_ops = &ice_dcf_eth_dev_ops;
>  	eth_dev->rx_pkt_burst = ice_dcf_recv_pkts;
>  	eth_dev->tx_pkt_burst = ice_dcf_xmit_pkts;
> --
> 2.27.0