iwlwifi: mvm: rs: refactor rate scale action decision

Extract the scale action decision to a different function
in preparation of modifying it. While at it also convert
the scale action values from hardcoded values to a clear enum.

Signed-off-by: Eyal Shapira <eyal@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c
index 6d0bd45b0791a9e684a9b283d86da614a083c614..62b29d7f80f01d2760829f3ddbae584919e74875 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rs.c
@@ -130,6 +130,12 @@ static const struct iwl_rs_rate_info iwl_rates[IWL_RATE_COUNT] = {
        IWL_DECLARE_MCS_RATE(9),                 /* MCS 9 */
 };
 
+enum rs_action {
+       RS_ACTION_STAY = 0,
+       RS_ACTION_DOWNSCALE = -1,
+       RS_ACTION_UPSCALE = 1,
+};
+
 enum rs_column_mode {
        RS_INVALID = 0,
        RS_LEGACY,
@@ -1616,6 +1622,97 @@ err:
        return -1;
 }
 
+static enum rs_action rs_get_rate_action(struct iwl_mvm *mvm,
+                                        struct iwl_scale_tbl_info *tbl,
+                                        s32 sr, int low, int high,
+                                        int current_tpt,
+                                        int low_tpt, int high_tpt)
+{
+       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;
+               }
+       }
+
+       /* 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)) {
+               IWL_DEBUG_RATE(mvm,
+                              "Both high and low are worse. "
+                              "Maintain rate\n");
+               action = RS_ACTION_STAY;
+       }
+
+       /* 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;
+                       }
+
+               /* 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;
+                       }
+               }
+       }
+
+       /* 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])))) {
+               IWL_DEBUG_RATE(mvm,
+                              "Sanity check failed. Maintain rate\n");
+               action = RS_ACTION_STAY;
+       }
+
+       return action;
+}
 
 /*
  * Do rate scaling and search for new modulation mode.
@@ -1636,7 +1733,7 @@ static void rs_rate_scale_perform(struct iwl_mvm *mvm,
        int low_tpt = IWL_INVALID_VALUE;
        int high_tpt = IWL_INVALID_VALUE;
        u32 fail_count;
-       s8 scale_action = 0;
+       enum rs_action scale_action = RS_ACTION_STAY;
        u16 rate_mask;
        u8 update_lq = 0;
        struct iwl_scale_tbl_info *tbl, *tbl1;
@@ -1830,85 +1927,8 @@ static void rs_rate_scale_perform(struct iwl_mvm *mvm,
                       rs_pretty_lq_type(rate->type), index, current_tpt, sr,
                       low, high, low_tpt, high_tpt);
 
-       scale_action = 0;
-
-       /* 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");
-               scale_action = -1;
-       /* 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");
-                       scale_action = 1;
-               } else if (low != IWL_RATE_INVALID) {
-                       IWL_DEBUG_RATE(mvm,
-                                      "Remain in current rate\n");
-                       scale_action = 0;
-               }
-       }
-
-       /* 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)) {
-               IWL_DEBUG_RATE(mvm,
-                              "Both high and low are worse. "
-                              "Maintain rate\n");
-               scale_action = 0;
-       }
-
-       /* 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");
-                               scale_action = 1;
-                       } else {
-                               IWL_DEBUG_RATE(mvm,
-                                              "Higher rate isn't better OR "
-                                              "no good SR. Maintain rate\n");
-                               scale_action = 0;
-                       }
-
-               /* 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");
-                               scale_action = -1;
-                       } else if (sr >= IWL_RATE_INCREASE_TH) {
-                               IWL_DEBUG_RATE(mvm,
-                                              "Lower rate isn't better and "
-                                              "good SR. Increase rate\n");
-                               scale_action = 1;
-                       }
-               }
-       }
-
-       /* Sanity check; asked for decrease, but success rate or throughput
-        * has been good at old rate.  Don't change it. */
-       if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
-           ((sr > IWL_RATE_HIGH_TH) ||
-            (current_tpt > (100 * tbl->expected_tpt[low])))) {
-               IWL_DEBUG_RATE(mvm,
-                              "Sanity check failed. Maintain rate\n");
-               scale_action = 0;
-       }
+       scale_action = rs_get_rate_action(mvm, tbl, sr, low, high,
+                                         current_tpt, low_tpt, high_tpt);
 
        /* Force a search in case BT doesn't like us being in MIMO */
        if (is_mimo(rate) &&
@@ -1920,7 +1940,7 @@ static void rs_rate_scale_perform(struct iwl_mvm *mvm,
        }
 
        switch (scale_action) {
-       case -1:
+       case RS_ACTION_DOWNSCALE:
                /* Decrease starting rate, update uCode's rate table */
                if (low != IWL_RATE_INVALID) {
                        update_lq = 1;
@@ -1931,7 +1951,7 @@ static void rs_rate_scale_perform(struct iwl_mvm *mvm,
                }
 
                break;
-       case 1:
+       case RS_ACTION_UPSCALE:
                /* Increase starting rate, update uCode's rate table */
                if (high != IWL_RATE_INVALID) {
                        update_lq = 1;
@@ -1942,7 +1962,7 @@ static void rs_rate_scale_perform(struct iwl_mvm *mvm,
                }
 
                break;
-       case 0:
+       case RS_ACTION_STAY:
                /* No change */
        default:
                break;