mwifiex: scan less channels per scan command to improve Tx traffic
Currently 4 channels are scanned per scan command. if scan request
is issued by user during Tx traffic, radio will be out of channel
for "4 * per_chan_scan_time" for each scan command and will not be
able to receive Rx packets. This adds delay in data traffic. We can
minimize it by reducing number of channels scanned per scan command
in this scenario.
We can not always scan 1 channel per scan command due to limitation
of number of command buffers. So we add code to decide number of
channels scanned per scan command in associated state.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index ea2f1bd..efaf26c 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -28,7 +28,10 @@
/* The maximum number of channels the firmware can scan per command */
#define MWIFIEX_MAX_CHANNELS_PER_SPECIFIC_SCAN 14
-#define MWIFIEX_CHANNELS_PER_SCAN_CMD 4
+#define MWIFIEX_DEF_CHANNELS_PER_SCAN_CMD 4
+#define MWIFIEX_LIMIT_1_CHANNEL_PER_SCAN_CMD 15
+#define MWIFIEX_LIMIT_2_CHANNELS_PER_SCAN_CMD 27
+#define MWIFIEX_LIMIT_3_CHANNELS_PER_SCAN_CMD 35
/* Memory needed to store a max sized Channel List TLV for a firmware scan */
#define CHAN_TLV_MAX_SIZE (sizeof(struct mwifiex_ie_types_header) \
@@ -471,7 +474,7 @@
* This routine is used for any scan that is not provided with a
* specific channel list to scan.
*/
-static void
+static int
mwifiex_scan_create_channel_list(struct mwifiex_private *priv,
const struct mwifiex_user_scan_cfg
*user_scan_in,
@@ -528,6 +531,7 @@
}
}
+ return chan_idx;
}
/*
@@ -727,6 +731,7 @@
u32 num_probes;
u32 ssid_len;
u32 chan_idx;
+ u32 chan_num;
u32 scan_type;
u16 scan_dur;
u8 channel;
@@ -850,7 +855,7 @@
if (*filtered_scan)
*max_chan_per_scan = MWIFIEX_MAX_CHANNELS_PER_SPECIFIC_SCAN;
else
- *max_chan_per_scan = MWIFIEX_CHANNELS_PER_SCAN_CMD;
+ *max_chan_per_scan = MWIFIEX_DEF_CHANNELS_PER_SCAN_CMD;
/* If the input config or adapter has the number of Probes set,
add tlv */
@@ -962,13 +967,28 @@
dev_dbg(adapter->dev,
"info: Scan: Scanning current channel only\n");
}
-
+ chan_num = chan_idx;
} else {
dev_dbg(adapter->dev,
"info: Scan: Creating full region channel list\n");
- mwifiex_scan_create_channel_list(priv, user_scan_in,
- scan_chan_list,
- *filtered_scan);
+ chan_num = mwifiex_scan_create_channel_list(priv, user_scan_in,
+ scan_chan_list,
+ *filtered_scan);
+ }
+
+ /*
+ * In associated state we will reduce the number of channels scanned per
+ * scan command to avoid any traffic delay/loss. This number is decided
+ * based on total number of channels to be scanned due to constraints
+ * of command buffers.
+ */
+ if (priv->media_connected) {
+ if (chan_num < MWIFIEX_LIMIT_1_CHANNEL_PER_SCAN_CMD)
+ *max_chan_per_scan = 1;
+ else if (chan_num < MWIFIEX_LIMIT_2_CHANNELS_PER_SCAN_CMD)
+ *max_chan_per_scan = 2;
+ else if (chan_num < MWIFIEX_LIMIT_3_CHANNELS_PER_SCAN_CMD)
+ *max_chan_per_scan = 3;
}
}