From fb9eb027fbc90e21cbda18379d85f8603e1f28b9 Mon Sep 17 00:00:00 2001 From: Horatiu Vultur Date: Thu, 10 Mar 2022 09:40:05 +0100 Subject: [PATCH] net: lan966x: Improve the CPU TX bitrate. When doing manual injection of the frame, it is required to check if the TX FIFO is ready to accept the next word of the frame. For this we are using 'readx_poll_timeout_atomic', the only problem is that before it actually checks the status, is determining the time when to finish polling the status. Which seems to be an expensive operation. Therefore check the status of the TX FIFO before calling 'readx_poll_timeout_atomic'. Doing this will improve the TX bitrate by ~70%. Because 99% the FIFO is ready by that time. The measurements were done using iperf3. Before: [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.03 sec 55.2 MBytes 46.2 Mbits/sec 0 sender [ 5] 0.00-10.04 sec 53.8 MBytes 45.0 Mbits/sec receiver After: [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.10 sec 95.0 MBytes 78.9 Mbits/sec 0 sender [ 5] 0.00-10.11 sec 95.0 MBytes 78.8 Mbits/sec receiver Signed-off-by: Horatiu Vultur Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c index 81c01665d01e..e1bcb28039dc 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c @@ -185,6 +185,9 @@ static int lan966x_port_inj_ready(struct lan966x *lan966x, u8 grp) { u32 val; + if (lan_rd(lan966x, QS_INJ_STATUS) & QS_INJ_STATUS_FIFO_RDY_SET(BIT(grp))) + return 0; + return readx_poll_timeout_atomic(lan966x_port_inj_status, lan966x, val, QS_INJ_STATUS_FIFO_RDY_GET(val) & BIT(grp), READL_SLEEP_US, READL_TIMEOUT_US); -- 2.20.1