ath5k: Adaptive Noise Immunity (ANI) Implementation

This is an Adaptive Noise Imunity (ANI) implementation for ath5k. I have looked
at both ath9k and HAL sources (they are nearly the same), and even though i
have implemented some things differently, the basic algorithm is practically
the same, for now. I hope that this can serve as a clean start to improve the
algorithm later.

This also adds a possibility to manually control ANI settings, right now only
thru a debugfs file:
  * set lowest sensitivity (=highest noise immunity):
	echo sens-low > /sys/kernel/debug/ath5k/phy0/ani
  * set highest sensitivity (=lowest noise immunity):
	echo sens-high > /sys/kernel/debug/ath5k/phy0/ani
  * automatically control immunity (default):
	echo ani-on > /sys/kernel/debug/ath5k/phy0/ani
  * to see the parameters in use and watch them change:
	cat /sys/kernel/debug/ath5k/phy0/ani

Manually setting sensitivity will turn the automatic control off. You can also
control each of the five immunity parameters (noise immunity, spur immunity,
firstep, ofdm weak signal detection, cck weak signal detection) manually thru
the debugfs file.

This is tested on AR5414 and nearly doubles the thruput in a noisy 2GHz band.

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index 90247dc74198..6fb5c5ffa5b1 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -69,6 +69,7 @@ module_param_named(debug, ath5k_debug, uint, 0);
 
 #include <linux/seq_file.h>
 #include "reg.h"
+#include "ani.h"
 
 static struct dentry *ath5k_global_debugfs;
 
@@ -307,6 +308,7 @@ static const struct {
 	{ ATH5K_DEBUG_DUMP_TX,	"dumptx",	"print transmit skb content" },
 	{ ATH5K_DEBUG_DUMPBANDS, "dumpbands",	"dump bands" },
 	{ ATH5K_DEBUG_TRACE,	"trace",	"trace function calls" },
+	{ ATH5K_DEBUG_ANI,	"ani",		"adaptive noise immunity" },
 	{ ATH5K_DEBUG_ANY,	"all",		"show all debug levels" },
 };
 
@@ -573,6 +575,160 @@ static const struct file_operations fops_frameerrors = {
 };
 
 
+/* debugfs: ani */
+
+static ssize_t read_file_ani(struct file *file, char __user *user_buf,
+				   size_t count, loff_t *ppos)
+{
+	struct ath5k_softc *sc = file->private_data;
+	struct ath5k_statistics *st = &sc->stats;
+	struct ath5k_ani_state *as = &sc->ani_state;
+
+	char buf[700];
+	unsigned int len = 0;
+
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"HW has PHY error counters:\t%s\n",
+			sc->ah->ah_capabilities.cap_has_phyerr_counters ?
+			"yes" : "no");
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"HW max spur immunity level:\t%d\n",
+			as->max_spur_level);
+	len += snprintf(buf+len, sizeof(buf)-len,
+		"\nANI state\n--------------------------------------------\n");
+	len += snprintf(buf+len, sizeof(buf)-len, "operating mode:\t\t\t");
+	switch (as->ani_mode) {
+	case ATH5K_ANI_MODE_OFF:
+		len += snprintf(buf+len, sizeof(buf)-len, "OFF\n");
+		break;
+	case ATH5K_ANI_MODE_MANUAL_LOW:
+		len += snprintf(buf+len, sizeof(buf)-len,
+			"MANUAL LOW\n");
+		break;
+	case ATH5K_ANI_MODE_MANUAL_HIGH:
+		len += snprintf(buf+len, sizeof(buf)-len,
+			"MANUAL HIGH\n");
+		break;
+	case ATH5K_ANI_MODE_AUTO:
+		len += snprintf(buf+len, sizeof(buf)-len, "AUTO\n");
+		break;
+	default:
+		len += snprintf(buf+len, sizeof(buf)-len,
+			"??? (not good)\n");
+		break;
+	}
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"noise immunity level:\t\t%d\n",
+			as->noise_imm_level);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"spur immunity level:\t\t%d\n",
+			as->spur_level);
+	len += snprintf(buf+len, sizeof(buf)-len, "firstep level:\t\t\t%d\n",
+			as->firstep_level);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"OFDM weak signal detection:\t%s\n",
+			as->ofdm_weak_sig ? "on" : "off");
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"CCK weak signal detection:\t%s\n",
+			as->cck_weak_sig ? "on" : "off");
+
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"\nMIB INTERRUPTS:\t\t%u\n",
+			st->mib_intr);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"beacon RSSI average:\t%d\n",
+			sc->ah->ah_beacon_rssi_avg.avg);
+	len += snprintf(buf+len, sizeof(buf)-len, "profcnt tx\t\t%u\t(%d%%)\n",
+			as->pfc_tx,
+			as->pfc_cycles > 0 ?
+			as->pfc_tx*100/as->pfc_cycles : 0);
+	len += snprintf(buf+len, sizeof(buf)-len, "profcnt rx\t\t%u\t(%d%%)\n",
+			as->pfc_rx,
+			as->pfc_cycles > 0 ?
+			as->pfc_rx*100/as->pfc_cycles : 0);
+	len += snprintf(buf+len, sizeof(buf)-len, "profcnt busy\t\t%u\t(%d%%)\n",
+			as->pfc_busy,
+			as->pfc_cycles > 0 ?
+			as->pfc_busy*100/as->pfc_cycles : 0);
+	len += snprintf(buf+len, sizeof(buf)-len, "profcnt cycles\t\t%u\n",
+			as->pfc_cycles);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"listen time\t\t%d\tlast: %d\n",
+			as->listen_time, as->last_listen);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"OFDM errors\t\t%u\tlast: %u\tsum: %u\n",
+			as->ofdm_errors, as->last_ofdm_errors,
+			as->sum_ofdm_errors);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"CCK errors\t\t%u\tlast: %u\tsum: %u\n",
+			as->cck_errors, as->last_cck_errors,
+			as->sum_cck_errors);
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"AR5K_PHYERR_CNT1\t%x\t(=%d)\n",
+			ath5k_hw_reg_read(sc->ah, AR5K_PHYERR_CNT1),
+			ATH5K_ANI_OFDM_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX -
+			ath5k_hw_reg_read(sc->ah, AR5K_PHYERR_CNT1)));
+	len += snprintf(buf+len, sizeof(buf)-len,
+			"AR5K_PHYERR_CNT2\t%x\t(=%d)\n",
+			ath5k_hw_reg_read(sc->ah, AR5K_PHYERR_CNT2),
+			ATH5K_ANI_CCK_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX -
+			ath5k_hw_reg_read(sc->ah, AR5K_PHYERR_CNT2)));
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t write_file_ani(struct file *file,
+				 const char __user *userbuf,
+				 size_t count, loff_t *ppos)
+{
+	struct ath5k_softc *sc = file->private_data;
+	char buf[20];
+
+	if (copy_from_user(buf, userbuf, min(count, sizeof(buf))))
+		return -EFAULT;
+
+	if (strncmp(buf, "sens-low", 8) == 0) {
+		ath5k_ani_init(sc->ah, ATH5K_ANI_MODE_MANUAL_HIGH);
+	} else if (strncmp(buf, "sens-high", 9) == 0) {
+		ath5k_ani_init(sc->ah, ATH5K_ANI_MODE_MANUAL_LOW);
+	} else if (strncmp(buf, "ani-off", 7) == 0) {
+		ath5k_ani_init(sc->ah, ATH5K_ANI_MODE_OFF);
+	} else if (strncmp(buf, "ani-on", 6) == 0) {
+		ath5k_ani_init(sc->ah, ATH5K_ANI_MODE_AUTO);
+	} else if (strncmp(buf, "noise-low", 9) == 0) {
+		ath5k_ani_set_noise_immunity_level(sc->ah, 0);
+	} else if (strncmp(buf, "noise-high", 10) == 0) {
+		ath5k_ani_set_noise_immunity_level(sc->ah,
+						   ATH5K_ANI_MAX_NOISE_IMM_LVL);
+	} else if (strncmp(buf, "spur-low", 8) == 0) {
+		ath5k_ani_set_spur_immunity_level(sc->ah, 0);
+	} else if (strncmp(buf, "spur-high", 9) == 0) {
+		ath5k_ani_set_spur_immunity_level(sc->ah,
+						  sc->ani_state.max_spur_level);
+	} else if (strncmp(buf, "fir-low", 7) == 0) {
+		ath5k_ani_set_firstep_level(sc->ah, 0);
+	} else if (strncmp(buf, "fir-high", 8) == 0) {
+		ath5k_ani_set_firstep_level(sc->ah, ATH5K_ANI_MAX_FIRSTEP_LVL);
+	} else if (strncmp(buf, "ofdm-off", 8) == 0) {
+		ath5k_ani_set_ofdm_weak_signal_detection(sc->ah, false);
+	} else if (strncmp(buf, "ofdm-on", 7) == 0) {
+		ath5k_ani_set_ofdm_weak_signal_detection(sc->ah, true);
+	} else if (strncmp(buf, "cck-off", 7) == 0) {
+		ath5k_ani_set_cck_weak_signal_detection(sc->ah, false);
+	} else if (strncmp(buf, "cck-on", 6) == 0) {
+		ath5k_ani_set_cck_weak_signal_detection(sc->ah, true);
+	}
+	return count;
+}
+
+static const struct file_operations fops_ani = {
+	.read = read_file_ani,
+	.write = write_file_ani,
+	.open = ath5k_debugfs_open,
+	.owner = THIS_MODULE,
+};
+
+
 /* init */
 
 void
@@ -611,6 +767,11 @@ ath5k_debug_init_device(struct ath5k_softc *sc)
 				S_IWUSR | S_IRUSR,
 				sc->debug.debugfs_phydir, sc,
 				&fops_frameerrors);
+
+	sc->debug.debugfs_ani = debugfs_create_file("ani",
+				S_IWUSR | S_IRUSR,
+				sc->debug.debugfs_phydir, sc,
+				&fops_ani);
 }
 
 void
@@ -628,6 +789,7 @@ ath5k_debug_finish_device(struct ath5k_softc *sc)
 	debugfs_remove(sc->debug.debugfs_reset);
 	debugfs_remove(sc->debug.debugfs_antenna);
 	debugfs_remove(sc->debug.debugfs_frameerrors);
+	debugfs_remove(sc->debug.debugfs_ani);
 	debugfs_remove(sc->debug.debugfs_phydir);
 }