[PATCH] iwlwifi: set fixed rate through debugfs

This patch adds fixed rate setting through debugfs

$ echo <rate_n_flags> > \
/sys/kernel/debug/ieee80211/phy<X>/stations/<mac>/rate_scale_table

Currently there is no way to turn to rate scaling working again.
Will be fixed in later.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 70 insertions, 2 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
index c4b8ca128495..e5f8cce443ba 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965-rs.c
@@ -123,7 +123,9 @@ struct iwl_rate_scale_priv {
         struct iwl_link_quality_cmd lq;
         struct iwl_scale_tbl_info lq_info[LQ_SIZE];
 #ifdef CONFIG_MAC80211_DEBUGFS
-       struct dentry *rs_sta_dbgfs_scale_table_file;
+        struct dentry *rs_sta_dbgfs_scale_table_file;
+        struct iwl_rate dbg_fixed;
+        struct iwl_priv *drv;
 #endif
 };
 
@@ -136,6 +138,14 @@ static void rs_fill_link_cmd(struct iwl_rate_scale_priv *lq_data,
                              struct iwl_link_quality_cmd *tbl);
 
 
+#ifdef CONFIG_MAC80211_DEBUGFS
+static void rs_dbgfs_set_mcs(struct iwl_rate_scale_priv *rs_priv,
+                                struct iwl_rate *mcs, int index);
+#else
+static void rs_dbgfs_set_mcs(struct iwl_rate_scale_priv *rs_priv,
+                                struct iwl_rate *mcs, int index)
+{}
+#endif
 static s32 expected_tpt_A[IWL_RATE_COUNT] = {
         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186, 186
 };
@@ -1866,6 +1876,9 @@ static void rs_rate_init(void *priv_rate, void *priv_sta,
         IWL_DEBUG_HT("MIMO RATE 0x%X SISO MASK 0x%X\n", crl->active_siso_rate,
                      crl->active_mimo_rate);
 #endif /*CONFIG_IWLWIFI_HT*/
+#ifdef CONFIG_MAC80211_DEBUGFS
+        crl->drv = priv;
+#endif
 
         if (priv->assoc_station_added)
                 priv->lq_mngr.lq_ready = 1;
@@ -1885,6 +1898,8 @@ static void rs_fill_link_cmd(struct iwl_rate_scale_priv *lq_data,
         struct iwl_rate new_rate;
         struct iwl_scale_tbl_info tbl_type = { 0 };
 
+        rs_dbgfs_set_mcs(lq_data, tx_mcs, index);
+
         rs_get_tbl_info_from_mcs(tx_mcs, lq_data->phymode,
                                   &tbl_type, &rate_idx);
 
@@ -1919,6 +1934,8 @@ static void rs_fill_link_cmd(struct iwl_rate_scale_priv *lq_data,
                                         ant_toggle_count = 1;
                                 }
                         }
+
+                        rs_dbgfs_set_mcs(lq_data, &new_rate, index);
                         lq_cmd->rs_table[index].rate_n_flags =
                                         cpu_to_le32(new_rate.rate_n_flags);
                         repeat_rate--;
@@ -1947,6 +1964,7 @@ static void rs_fill_link_cmd(struct iwl_rate_scale_priv *lq_data,
 
                 use_ht_possible = 0;
 
+                rs_dbgfs_set_mcs(lq_data, &new_rate, index);
                 lq_cmd->rs_table[index].rate_n_flags =
                                 cpu_to_le32(new_rate.rate_n_flags);
 
@@ -2002,7 +2020,54 @@ static int open_file_generic(struct inode *inode, struct file *file)
         file->private_data = inode->i_private;
         return 0;
 }
+static void rs_dbgfs_set_mcs(struct iwl_rate_scale_priv *rs_priv,
+                                struct iwl_rate *mcs, int index)
+{
+        const u32 cck_rate = 0x820A;
+        if (rs_priv->dbg_fixed.rate_n_flags) {
+                if (index < 12)
+                        mcs->rate_n_flags = rs_priv->dbg_fixed.rate_n_flags;
+                else
+                        mcs->rate_n_flags = cck_rate;
+                IWL_DEBUG_RATE("Fixed rate ON\n");
+                return;
+        }
+
+        IWL_DEBUG_RATE("Fixed rate OFF\n");
+}
 
+static ssize_t rs_sta_dbgfs_scale_table_write(struct file *file,
+                        const char __user *user_buf, size_t count, loff_t *ppos)
+{
+        struct iwl_rate_scale_priv *rs_priv = file->private_data;
+        char buf[64];
+        int buf_size;
+        u32 parsed_rate;
+
+        memset(buf, 0, sizeof(buf));
+        buf_size = min(count, sizeof(buf) -  1);
+        if (copy_from_user(buf, user_buf, buf_size))
+                return -EFAULT;
+
+        if (sscanf(buf, "%x", &parsed_rate) == 1)
+                rs_priv->dbg_fixed.rate_n_flags = parsed_rate;
+        else
+                rs_priv->dbg_fixed.rate_n_flags = 0;
+
+        rs_priv->active_rate = 0x0FFF;
+        rs_priv->active_siso_rate = 0x1FD0;
+        rs_priv->active_mimo_rate = 0x1FD0;
+
+        IWL_DEBUG_RATE("sta_id %d rate 0x%X\n",
+                rs_priv->lq.sta_id, rs_priv->dbg_fixed.rate_n_flags);
+
+        if (rs_priv->dbg_fixed.rate_n_flags) {
+                rs_fill_link_cmd(rs_priv, &rs_priv->dbg_fixed, &rs_priv->lq);
+                rs_send_lq_cmd(rs_priv->drv, &rs_priv->lq, CMD_ASYNC);
+        }
+
+        return count;
+}
 static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
                         char __user *user_buf, size_t count, loff_t *ppos)
 {
@@ -2013,9 +2078,11 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
         struct iwl_rate_scale_priv *rs_priv = file->private_data;
 
         desc += sprintf(buff+desc, "sta_id %d\n", rs_priv->lq.sta_id);
-        desc += sprintf(buff+desc, "failed=%d success=%d rate=%X\n",
+        desc += sprintf(buff+desc, "failed=%d success=%d rate=0%X\n",
                         rs_priv->total_failed, rs_priv->total_success,
                         rs_priv->active_rate);
+        desc += sprintf(buff+desc, "fixed rate 0x%X\n",
+                        rs_priv->dbg_fixed.rate_n_flags);
         desc += sprintf(buff+desc, "general:"
                 "flags=0x%X mimo-d=%d s-ant0x%x d-ant=0x%x\n",
                 rs_priv->lq.general_params.flags,
@@ -2045,6 +2112,7 @@ static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
 }
 
 static const struct file_operations rs_sta_dbgfs_scale_table_ops = {
+        .write = rs_sta_dbgfs_scale_table_write,
         .read = rs_sta_dbgfs_scale_table_read,
         .open = open_file_generic,
 };