From 1a92497dc3f90280aebfea8044741d75438110e0 Mon Sep 17 00:00:00 2001 From: Yonglong Liu Date: Wed, 11 Sep 2019 10:40:35 +0800 Subject: [PATCH] net: hns3: fix shaper parameter algorithm Currently when hns3 driver configures the tm shaper to limit bandwidth below 20Mbit using the parameters calculated by hclge_shaper_para_calc(), the actual bandwidth limited by tm hardware module is not accurate enough, for example, 1.28 Mbit when the user is configuring 1 Mbit. This patch adjusts the ir_calc to be closer to ir, and always calculate the ir_b parameter when user is configuring a small bandwidth. Also, removes an unnecessary parenthesis when calculating denominator. Fixes: 848440544b41 ("net: hns3: Add support of TX Scheduler & Shaper to HNS3 driver") Signed-off-by: Yonglong Liu Signed-off-by: Huazhong Tan Signed-off-by: David S. Miller --- drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c index e829101d576c..9f0e35f27789 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c @@ -81,16 +81,13 @@ static int hclge_shaper_para_calc(u32 ir, u8 shaper_level, return 0; } else if (ir_calc > ir) { /* Increasing the denominator to select ir_s value */ - while (ir_calc > ir) { + while (ir_calc >= ir && ir) { ir_s_calc++; ir_calc = DIVISOR_IR_B_126 / (tick * (1 << ir_s_calc)); } - if (ir_calc == ir) - *ir_b = 126; - else - *ir_b = (ir * tick * (1 << ir_s_calc) + - (DIVISOR_CLK >> 1)) / DIVISOR_CLK; + *ir_b = (ir * tick * (1 << ir_s_calc) + (DIVISOR_CLK >> 1)) / + DIVISOR_CLK; } else { /* Increasing the numerator to select ir_u value */ u32 numerator; @@ -104,7 +101,7 @@ static int hclge_shaper_para_calc(u32 ir, u8 shaper_level, if (ir_calc == ir) { *ir_b = 126; } else { - u32 denominator = (DIVISOR_CLK * (1 << --ir_u_calc)); + u32 denominator = DIVISOR_CLK * (1 << --ir_u_calc); *ir_b = (ir * tick + (denominator >> 1)) / denominator; } } -- 2.30.2