From e53839eb9882c99d3781eab0fe1b2d4369a6a2cc Mon Sep 17 00:00:00 2001 From: Eyal Shapira Date: Sun, 6 Apr 2014 02:42:18 +0300 Subject: [PATCH] iwlwifi: mvm: rs: fix and cleanup rs_get_rate_action Change the down/upscale decision logic a bit to be based on different success ratio thresholds. This fixes the implementation compared to the rate scale algorithm which was planned to yield optimal results. Also fix a case where a lower rate wasn't explored despite being a potential for better throughput. While at it rewrite rs_get_rate_action to be more clear and clean. Cc: [3.14] Signed-off-by: Eyal Shapira Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/rs.c | 127 ++++++++++++-------------- drivers/net/wireless/iwlwifi/mvm/rs.h | 1 + 2 files changed, 60 insertions(+), 68 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c index cd32ad54384..97b8fac214a 100644 --- a/drivers/net/wireless/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/iwlwifi/mvm/rs.c @@ -1658,85 +1658,76 @@ static enum rs_action rs_get_rate_action(struct iwl_mvm *mvm, { enum rs_action action = RS_ACTION_STAY; - /* Too many failures, decrease rate */ if ((sr <= RS_SR_FORCE_DECREASE) || (current_tpt == 0)) { IWL_DEBUG_RATE(mvm, - "decrease rate because of low SR\n"); - action = RS_ACTION_DOWNSCALE; - /* No throughput measured yet for adjacent rates; try increase. */ - } else if ((low_tpt == IWL_INVALID_VALUE) && - (high_tpt == IWL_INVALID_VALUE)) { - if (high != IWL_RATE_INVALID && sr >= IWL_RATE_INCREASE_TH) { - IWL_DEBUG_RATE(mvm, - "Good SR and no high rate measurement. " - "Increase rate\n"); - action = RS_ACTION_UPSCALE; - } else if (low != IWL_RATE_INVALID) { - IWL_DEBUG_RATE(mvm, - "Remain in current rate\n"); - action = RS_ACTION_STAY; - } + "Decrease rate because of low SR\n"); + return RS_ACTION_DOWNSCALE; } - /* Both adjacent throughputs are measured, but neither one has better - * throughput; we're using the best rate, don't change it! - */ - else if ((low_tpt != IWL_INVALID_VALUE) && - (high_tpt != IWL_INVALID_VALUE) && - (low_tpt < current_tpt) && - (high_tpt < current_tpt)) { + if ((low_tpt == IWL_INVALID_VALUE) && + (high_tpt == IWL_INVALID_VALUE) && + (high != IWL_RATE_INVALID)) { IWL_DEBUG_RATE(mvm, - "Both high and low are worse. " - "Maintain rate\n"); - action = RS_ACTION_STAY; + "No data about high/low rates. Increase rate\n"); + return RS_ACTION_UPSCALE; } - /* At least one adjacent rate's throughput is measured, - * and may have better performance. - */ - else { - /* Higher adjacent rate's throughput is measured */ - if (high_tpt != IWL_INVALID_VALUE) { - /* Higher rate has better throughput */ - if (high_tpt > current_tpt && - sr >= IWL_RATE_INCREASE_TH) { - IWL_DEBUG_RATE(mvm, - "Higher rate is better and good " - "SR. Increate rate\n"); - action = RS_ACTION_UPSCALE; - } else { - IWL_DEBUG_RATE(mvm, - "Higher rate isn't better OR " - "no good SR. Maintain rate\n"); - action = RS_ACTION_STAY; - } + if ((high_tpt == IWL_INVALID_VALUE) && + (high != IWL_RATE_INVALID) && + (low_tpt != IWL_INVALID_VALUE) && + (low_tpt < current_tpt)) { + IWL_DEBUG_RATE(mvm, + "No data about high rate and low rate is worse. Increase rate\n"); + return RS_ACTION_UPSCALE; + } - /* Lower adjacent rate's throughput is measured */ - } else if (low_tpt != IWL_INVALID_VALUE) { - /* Lower rate has better throughput */ - if (low_tpt > current_tpt) { - IWL_DEBUG_RATE(mvm, - "Lower rate is better. " - "Decrease rate\n"); - action = RS_ACTION_DOWNSCALE; - } else if (sr >= IWL_RATE_INCREASE_TH) { - IWL_DEBUG_RATE(mvm, - "Lower rate isn't better and " - "good SR. Increase rate\n"); - action = RS_ACTION_UPSCALE; - } - } + if ((high_tpt != IWL_INVALID_VALUE) && + (high_tpt > current_tpt)) { + IWL_DEBUG_RATE(mvm, + "Higher rate is better. Increate rate\n"); + return RS_ACTION_UPSCALE; } - /* Sanity check; asked for decrease, but success rate or throughput - * has been good at old rate. Don't change it. - */ - if ((action == RS_ACTION_DOWNSCALE) && (low != IWL_RATE_INVALID) && - ((sr > IWL_RATE_HIGH_TH) || - (current_tpt > (100 * tbl->expected_tpt[low])))) { + if ((low_tpt != IWL_INVALID_VALUE) && + (high_tpt != IWL_INVALID_VALUE) && + (low_tpt < current_tpt) && + (high_tpt < current_tpt)) { IWL_DEBUG_RATE(mvm, - "Sanity check failed. Maintain rate\n"); - action = RS_ACTION_STAY; + "Both high and low are worse. Maintain rate\n"); + return RS_ACTION_STAY; + } + + if ((low_tpt != IWL_INVALID_VALUE) && + (low_tpt > current_tpt)) { + IWL_DEBUG_RATE(mvm, + "Lower rate is better\n"); + action = RS_ACTION_DOWNSCALE; + goto out; + } + + if ((low_tpt == IWL_INVALID_VALUE) && + (low != IWL_RATE_INVALID)) { + IWL_DEBUG_RATE(mvm, + "No data about lower rate\n"); + action = RS_ACTION_DOWNSCALE; + goto out; + } + + IWL_DEBUG_RATE(mvm, "Maintain rate\n"); + +out: + if ((action == RS_ACTION_DOWNSCALE) && (low != IWL_RATE_INVALID)) { + if (sr >= RS_SR_NO_DECREASE) { + IWL_DEBUG_RATE(mvm, + "SR is above NO DECREASE. Avoid downscale\n"); + action = RS_ACTION_STAY; + } else if (current_tpt > (100 * tbl->expected_tpt[low])) { + IWL_DEBUG_RATE(mvm, + "Current TPT is higher than max expected in low rate. Avoid downscale\n"); + action = RS_ACTION_STAY; + } else { + IWL_DEBUG_RATE(mvm, "Decrease rate\n"); + } } return action; diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.h b/drivers/net/wireless/iwlwifi/mvm/rs.h index 9892d92d590..fbb476aadb2 100644 --- a/drivers/net/wireless/iwlwifi/mvm/rs.h +++ b/drivers/net/wireless/iwlwifi/mvm/rs.h @@ -156,6 +156,7 @@ enum { #define IWL_RATE_HIGH_TH 10880 /* 85% */ #define IWL_RATE_INCREASE_TH 6400 /* 50% */ #define RS_SR_FORCE_DECREASE 1920 /* 15% */ +#define RS_SR_NO_DECREASE 10880 /* 85% */ #define LINK_QUAL_AGG_TIME_LIMIT_DEF (4000) /* 4 milliseconds */ #define LINK_QUAL_AGG_TIME_LIMIT_MAX (8000) -- 2.41.0