On 14/04/2023 22.05, Jesper Dangaard Brouer wrote:
On 14/04/2023 17.49, 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.
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.
[...]
Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.14+
Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Reviewed-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
LGTM, thank for the adjustments :-)
Acked-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Tested-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
I can confirm that this patch fix the issue I experienced with igc.
This patch clearly fixes a bug in igc when writing the SRRCTL register.
(as bit 30 in register is "Timestamp Received Packet" which got cleared
before).
Florian might have found another bug around RX timestamps, but this
patch should be safe and sane to apply as is.
v2 -> v3: Refactor SRRCTL definitions to more human readable definitions
v1 -> v2: Fix indention
---
drivers/net/ethernet/intel/igc/igc_base.h | 11 ++++++++---
drivers/net/ethernet/intel/igc/igc_main.c | 7 +++++--
2 files changed, 13 insertions(+), 5 deletions(-)
