Re: [dpdk-dev] [PATCH v2] net/i40e: fix global register recovery

["Guo, Jia" <jia.guo@intel.com>]

Acked-by: Jeff Guo <jia.guo@intel.com>

> -----Original Message-----
> From: Xing, Beilei <beilei.xing@intel.com>
> Sent: Friday, November 20, 2020 4:50 PM
> To: dev@dpdk.org
> Cc: Guo, Jia <jia.guo@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> stable@dpdk.org
> Subject: [PATCH v2] net/i40e: fix global register recovery
> 
> From: Beilei Xing <beilei.xing@intel.com>
> 
> PMD configures the global register I40E_GLINT_CTL during device
> initialization to work around the Rx write back issue. But when a device is
> bound from DPDK to kernel, the global register is not recovered to the
> original state, it will cause kernel driver performance drop issue.
> This patch fixes this issue.
> 
> Fixes: be6c228d4da3 ("i40e: support Rx interrupt")
> Fixes: 4ab831449a1c ("net/i40e: fix interrupt conflict with multi-driver")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Beilei Xing <beilei.xing@intel.com>
> ---
> 
> v2 change:
>  - refine commit log
> 
>  drivers/net/i40e/i40e_ethdev.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index f54769c29d..2cb18ecc03 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -763,6 +763,21 @@ static inline void i40e_config_automask(struct
> i40e_pf *pf)
>  	I40E_WRITE_REG(hw, I40E_GLINT_CTL, val);  }
> 
> +static inline void i40e_clear_automask(struct i40e_pf *pf) {
> +	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
> +	uint32_t val;
> +
> +	val = I40E_READ_REG(hw, I40E_GLINT_CTL);
> +	val &= ~(I40E_GLINT_CTL_DIS_AUTOMASK_PF0_MASK |
> +		 I40E_GLINT_CTL_DIS_AUTOMASK_VF0_MASK);
> +
> +	if (!pf->support_multi_driver)
> +		val &= ~I40E_GLINT_CTL_DIS_AUTOMASK_N_MASK;
> +
> +	I40E_WRITE_REG(hw, I40E_GLINT_CTL, val); }
> +
>  #define I40E_FLOW_CONTROL_ETHERTYPE  0x8808
> 
>  /*
> @@ -2741,6 +2756,8 @@ i40e_dev_close(struct rte_eth_dev *dev)
>  	/* Remove all Traffic Manager configuration */
>  	i40e_tm_conf_uninit(dev);
> 
> +	i40e_clear_automask(pf);
> +
>  	hw->adapter_closed = 1;
>  	return ret;
>  }
> --
> 2.26.2