diff options
| author | Kurt Kanzenbach <kurt@linutronix.de> | 2021-11-22 12:19:31 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-23 20:11:05 -0800 |
| commit | c6d5f1933085f9a92ed5c256a859ab31c7a35f88 (patch) | |
| tree | 652bed7110baf5cc643b18ddd9194180453423bd /include/linux/stmmac.h | |
| parent | 2106efda785b55a8957efed9a52dfa28ee0d7280 (diff) | |
net: stmmac: Calculate CDC error only once
The clock domain crossing error (CDC) is calculated at every fetch of Tx or Rx
timestamps. It includes a division. Especially on arm32 based systems it is
expensive. It also requires two conditionals in the hotpath.
Add a compensation value cache to struct plat_stmmacenet_data and subtract it
unconditionally in the RX/TX functions which spares the conditionals.
The value is initialized to 0 and if supported calculated in the PTP
initialization code.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20211122111931.135135-1-kurt@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/stmmac.h')
| -rw-r--r-- | include/linux/stmmac.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h index a6f03b36fc4f..89b8e208cd7b 100644 --- a/include/linux/stmmac.h +++ b/include/linux/stmmac.h @@ -241,6 +241,7 @@ struct plat_stmmacenet_data { unsigned int clk_ref_rate; unsigned int mult_fact_100ns; s32 ptp_max_adj; + u32 cdc_error_adj; struct reset_control *stmmac_rst; struct reset_control *stmmac_ahb_rst; struct stmmac_axi *axi; |