[PATCH] net/hns3: fix inaccurate RTC time to read

[Dongdong Liu]

Hi Huisong

On 2023/1/9 16:23, Huisong Li wrote:
> The sequence of reading current RTC time register doesn't meet
> the hardware requirements, which causes this time obtained is
> the one before modifying RTC time.
>
> Fixes: 38b539d96eb6 ("net/hns3: support IEEE 1588 PTP")
> Cc: stable at dpdk.org
>
> Signed-off-by: Huisong Li <lihuisong at huawei.com>

Acked-by: Dongdong Liu <liudongdong3 at huawei.com>

Thanks,
Dongdong
> ---
>  drivers/net/hns3/hns3_ptp.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/hns3/hns3_ptp.c b/drivers/net/hns3/hns3_ptp.c
> index 6bbd85ba23..db3c007b12 100644
> --- a/drivers/net/hns3/hns3_ptp.c
> +++ b/drivers/net/hns3/hns3_ptp.c
> @@ -216,17 +216,21 @@ hns3_timesync_read_tx_timestamp(struct rte_eth_dev *dev,
>  int
>  hns3_timesync_read_time(struct rte_eth_dev *dev, struct timespec *ts)
>  {
> +#define HNS3_PTP_SEC_H_OFFSET	32
> +#define HNS3_PTP_SEC_H_MASK	0xFFFF
> +
>  	struct hns3_hw *hw = HNS3_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> +	uint32_t sec_hi, sec_lo;
>  	uint64_t ns, sec;
>
>  	if (!hns3_dev_get_support(hw, PTP))
>  		return -ENOTSUP;
>
> -	sec = hns3_read_dev(hw, HNS3_CURR_TIME_OUT_L);
> -	sec |= (uint64_t)(hns3_read_dev(hw, HNS3_CURR_TIME_OUT_H) & 0xFFFF)
> -		<< 32;
> -
>  	ns = hns3_read_dev(hw, HNS3_CURR_TIME_OUT_NS);
> +	sec_hi = hns3_read_dev(hw, HNS3_CURR_TIME_OUT_H) & HNS3_PTP_SEC_H_MASK;
> +	sec_lo = hns3_read_dev(hw, HNS3_CURR_TIME_OUT_L);
> +	sec = ((uint64_t)sec_hi << HNS3_PTP_SEC_H_OFFSET) | sec_lo;
> +
>  	ns += sec * NSEC_PER_SEC;
>  	*ts = rte_ns_to_timespec(ns);
>
>