diff options
| author | Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com> | 2022-09-21 10:49:40 +0800 |
|---|---|---|
| committer | Tony Nguyen <anthony.l.nguyen@intel.com> | 2022-11-02 11:38:22 -0700 |
| commit | 790835fcc0cb9992349ae3c9010dbc7321aaa24d (patch) | |
| tree | 38478bc37c982b90f11c45b302c3a7d8b9d65d5b /drivers/net/ethernet/intel/igc/igc_defines.h | |
| parent | 3e7b52e0eb9ef7e67c26072cb1c7a49a5cc356f5 (diff) | |
igc: Correct the launchtime offset
The launchtime offset should be corrected according to sections 7.5.2.6
Transmit Scheduling Latency of the Intel Ethernet I225/I226 Software
User Manual.
Software can compensate the latency between the transmission scheduling
and the time that packet is transmitted to the network by setting this
GTxOffset register. Without setting this register, there may be a
significant delay between the packet scheduling and the network point.
This patch helps to reduce the latency for each of the link speed.
Before:
10Mbps : 11000 - 13800 nanosecond
100Mbps : 1300 - 1700 nanosecond
1000Mbps : 190 - 600 nanosecond
2500Mbps : 1400 - 1700 nanosecond
After:
10Mbps : less than 750 nanosecond
100Mbps : less than 192 nanosecond
1000Mbps : less than 128 nanosecond
2500Mbps : less than 128 nanosecond
Test Setup:
Talker : Use l2_tai.c to generate the launchtime into packet payload.
Listener: Use timedump.c to compute the delta between packet arrival and
LaunchTime packet payload.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Acked-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/igc/igc_defines.h')
| -rw-r--r-- | drivers/net/ethernet/intel/igc/igc_defines.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h index 4f9d7f013a95..f7311aeb293b 100644 --- a/drivers/net/ethernet/intel/igc/igc_defines.h +++ b/drivers/net/ethernet/intel/igc/igc_defines.h @@ -400,6 +400,15 @@ #define IGC_DTXMXPKTSZ_TSN 0x19 /* 1600 bytes of max TX DMA packet size */ #define IGC_DTXMXPKTSZ_DEFAULT 0x98 /* 9728-byte Jumbo frames */ +/* Transmit Scheduling Latency */ +/* Latency between transmission scheduling (LaunchTime) and the time + * the packet is transmitted to the network in nanosecond. + */ +#define IGC_TXOFFSET_SPEED_10 0x000034BC +#define IGC_TXOFFSET_SPEED_100 0x00000578 +#define IGC_TXOFFSET_SPEED_1000 0x0000012C +#define IGC_TXOFFSET_SPEED_2500 0x00000578 + /* Time Sync Interrupt Causes */ #define IGC_TSICR_SYS_WRAP BIT(0) /* SYSTIM Wrap around. */ #define IGC_TSICR_TXTS BIT(1) /* Transmit Timestamp. */ |