Messages in this thread | | | From | Jesper Dangaard Brouer <> | Date | Thu, 13 Apr 2023 20:42:16 +0200 | Subject | Re: [PATCH net 1/1] igc: read before write to SRRCTL register |
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On 13/04/2023 17.12, Song Yoong Siang wrote: > igc_configure_rx_ring() function will be called as part of XDP program > setup. If Rx hardware timestamp is enabled prio to XDP program setup, > this timestamp enablement will be overwritten when buffer size is > written into SRRCTL register. >
Ah, I believe I have hit this bug with my igc patches. Thanks for fixing.
> Thus, this commit read the register value before write to SRRCTL > register. This commit is tested by using xdp_hw_metadata bpf selftest > tool. The tool enables Rx hardware timestamp and then attach XDP program > to igc driver. It will display hardware timestamp of UDP packet with > port number 9092. Below are detail of test steps and results. > > Command on DUT: > sudo ./xdp_hw_metadata <interface name> >
Why port 9092 ? The ./xdp_hw_metadata prog will redirect port 9091
> Command on Link Partner: > echo -n skb | nc -u -q1 <destination IPv4 addr> 9092 >
Again port 9092 ?
> Result before this patch: > skb hwtstamp is not found! > > Result after this patch: > found skb hwtstamp = 1677762212.590696226
I usually use this cmd to see if number is sane:
$ date -d @1677762212 2023-03-02T14:03:32 CET
> > Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy") > Cc: <stable@vger.kernel.org> # 5.14+ > Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com> > --- > drivers/net/ethernet/intel/igc/igc_base.h | 7 +++++-- > drivers/net/ethernet/intel/igc/igc_main.c | 5 ++++- > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/intel/igc/igc_base.h b/drivers/net/ethernet/intel/igc/igc_base.h > index 7a992befca24..b95007d51d13 100644 > --- a/drivers/net/ethernet/intel/igc/igc_base.h > +++ b/drivers/net/ethernet/intel/igc/igc_base.h > @@ -87,8 +87,11 @@ union igc_adv_rx_desc { > #define IGC_RXDCTL_SWFLUSH 0x04000000 /* Receive Software Flush */ > > /* SRRCTL bit definitions */ > -#define IGC_SRRCTL_BSIZEPKT_SHIFT 10 /* Shift _right_ */ > -#define IGC_SRRCTL_BSIZEHDRSIZE_SHIFT 2 /* Shift _left_ */ > +#define IGC_SRRCTL_BSIZEPKT_MASK GENMASK(6, 0) > +#define IGC_SRRCTL_BSIZEPKT_SHIFT 10 /* Shift _right_ */ > +#define IGC_SRRCTL_BSIZEHDRSIZE_MASK GENMASK(13, 8) > +#define IGC_SRRCTL_BSIZEHDRSIZE_SHIFT 2 /* Shift _left_ */ > +#define IGC_SRRCTL_DESCTYPE_MASK GENMASK(27, 25) > #define IGC_SRRCTL_DESCTYPE_ADV_ONEBUF 0x02000000 > > #endif /* _IGC_BASE_H */ > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c > index 25fc6c65209b..de7b21c2ccd6 100644 > --- a/drivers/net/ethernet/intel/igc/igc_main.c > +++ b/drivers/net/ethernet/intel/igc/igc_main.c > @@ -641,7 +641,10 @@ static void igc_configure_rx_ring(struct igc_adapter *adapter, > else > buf_size = IGC_RXBUFFER_2048; > > - srrctl = IGC_RX_HDR_LEN << IGC_SRRCTL_BSIZEHDRSIZE_SHIFT; > + srrctl = rd32(IGC_SRRCTL(reg_idx)); > + srrctl &= ~(IGC_SRRCTL_BSIZEPKT_MASK | IGC_SRRCTL_BSIZEHDRSIZE_MASK | > + IGC_SRRCTL_DESCTYPE_MASK); > + srrctl |= IGC_RX_HDR_LEN << IGC_SRRCTL_BSIZEHDRSIZE_SHIFT; > srrctl |= buf_size >> IGC_SRRCTL_BSIZEPKT_SHIFT; > srrctl |= IGC_SRRCTL_DESCTYPE_ADV_ONEBUF; >
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