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linux/drivers/net/wireless/ath/ath9k/calib.c
Felix Fietkau 4254bc1c4d ath9k_hw: fix a noise floor calibration related race condition
On AR5008-AR9002, other forms of calibration must not be started while
the noise floor calibration is running, as this can create invalid
readings which were sometimes not even recoverable by any further
calibration attempts.

This patch also ensures that the result of noise floor measurements
are processed faster and also allows the result of the initial
calibration on reset to make it into the NF history buffer

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04 15:27:37 -04:00

364 lines
9.2 KiB
C

/*
* Copyright (c) 2008-2009 Atheros Communications Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "hw.h"
#include "hw-ops.h"
/* Common calibration code */
/* We can tune this as we go by monitoring really low values */
#define ATH9K_NF_TOO_LOW -60
static int16_t ath9k_hw_get_nf_hist_mid(int16_t *nfCalBuffer)
{
int16_t nfval;
int16_t sort[ATH9K_NF_CAL_HIST_MAX];
int i, j;
for (i = 0; i < ATH9K_NF_CAL_HIST_MAX; i++)
sort[i] = nfCalBuffer[i];
for (i = 0; i < ATH9K_NF_CAL_HIST_MAX - 1; i++) {
for (j = 1; j < ATH9K_NF_CAL_HIST_MAX - i; j++) {
if (sort[j] > sort[j - 1]) {
nfval = sort[j];
sort[j] = sort[j - 1];
sort[j - 1] = nfval;
}
}
}
nfval = sort[(ATH9K_NF_CAL_HIST_MAX - 1) >> 1];
return nfval;
}
static void ath9k_hw_update_nfcal_hist_buffer(struct ath9k_nfcal_hist *h,
int16_t *nfarray)
{
int i;
for (i = 0; i < NUM_NF_READINGS; i++) {
h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
h[i].currIndex = 0;
if (h[i].invalidNFcount > 0) {
h[i].invalidNFcount--;
h[i].privNF = nfarray[i];
} else {
h[i].privNF =
ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
}
}
}
static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
enum ieee80211_band band,
int16_t *nft)
{
switch (band) {
case IEEE80211_BAND_5GHZ:
*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
break;
case IEEE80211_BAND_2GHZ:
*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
break;
default:
BUG_ON(1);
return false;
}
return true;
}
void ath9k_hw_reset_calibration(struct ath_hw *ah,
struct ath9k_cal_list *currCal)
{
int i;
ath9k_hw_setup_calibration(ah, currCal);
currCal->calState = CAL_RUNNING;
for (i = 0; i < AR5416_MAX_CHAINS; i++) {
ah->meas0.sign[i] = 0;
ah->meas1.sign[i] = 0;
ah->meas2.sign[i] = 0;
ah->meas3.sign[i] = 0;
}
ah->cal_samples = 0;
}
static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
struct ath9k_channel *chan)
{
struct ath_nf_limits *limit;
if (!chan || IS_CHAN_2GHZ(chan))
limit = &ah->nf_2g;
else
limit = &ah->nf_5g;
return limit->nominal;
}
/* This is done for the currently configured channel */
bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
{
struct ath_common *common = ath9k_hw_common(ah);
struct ieee80211_conf *conf = &common->hw->conf;
struct ath9k_cal_list *currCal = ah->cal_list_curr;
if (!ah->caldata)
return true;
if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
return true;
if (currCal == NULL)
return true;
if (currCal->calState != CAL_DONE) {
ath_print(common, ATH_DBG_CALIBRATE,
"Calibration state incorrect, %d\n",
currCal->calState);
return true;
}
if (!ath9k_hw_iscal_supported(ah, currCal->calData->calType))
return true;
ath_print(common, ATH_DBG_CALIBRATE,
"Resetting Cal %d state for channel %u\n",
currCal->calData->calType, conf->channel->center_freq);
ah->caldata->CalValid &= ~currCal->calData->calType;
currCal->calState = CAL_WAITING;
return false;
}
EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
{
if (ah->caldata)
ah->caldata->nfcal_pending = true;
REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
AR_PHY_AGC_CONTROL_ENABLE_NF);
if (update)
REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
else
REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
}
void ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
{
struct ath9k_nfcal_hist *h = NULL;
unsigned i, j;
int32_t val;
u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
struct ath_common *common = ath9k_hw_common(ah);
s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
if (ah->caldata)
h = ah->caldata->nfCalHist;
for (i = 0; i < NUM_NF_READINGS; i++) {
if (chainmask & (1 << i)) {
s16 nfval;
if (h)
nfval = h[i].privNF;
else
nfval = default_nf;
val = REG_READ(ah, ah->nf_regs[i]);
val &= 0xFFFFFE00;
val |= (((u32) nfval << 1) & 0x1ff);
REG_WRITE(ah, ah->nf_regs[i], val);
}
}
/*
* Load software filtered NF value into baseband internal minCCApwr
* variable.
*/
REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
AR_PHY_AGC_CONTROL_ENABLE_NF);
REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
/*
* Wait for load to complete, should be fast, a few 10s of us.
* The max delay was changed from an original 250us to 10000us
* since 250us often results in NF load timeout and causes deaf
* condition during stress testing 12/12/2009
*/
for (j = 0; j < 1000; j++) {
if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
AR_PHY_AGC_CONTROL_NF) == 0)
break;
udelay(10);
}
/*
* We timed out waiting for the noisefloor to load, probably due to an
* in-progress rx. Simply return here and allow the load plenty of time
* to complete before the next calibration interval. We need to avoid
* trying to load -50 (which happens below) while the previous load is
* still in progress as this can cause rx deafness. Instead by returning
* here, the baseband nf cal will just be capped by our present
* noisefloor until the next calibration timer.
*/
if (j == 1000) {
ath_print(common, ATH_DBG_ANY, "Timeout while waiting for nf "
"to load: AR_PHY_AGC_CONTROL=0x%x\n",
REG_READ(ah, AR_PHY_AGC_CONTROL));
return;
}
/*
* Restore maxCCAPower register parameter again so that we're not capped
* by the median we just loaded. This will be initial (and max) value
* of next noise floor calibration the baseband does.
*/
ENABLE_REGWRITE_BUFFER(ah);
for (i = 0; i < NUM_NF_READINGS; i++) {
if (chainmask & (1 << i)) {
val = REG_READ(ah, ah->nf_regs[i]);
val &= 0xFFFFFE00;
val |= (((u32) (-50) << 1) & 0x1ff);
REG_WRITE(ah, ah->nf_regs[i], val);
}
}
REGWRITE_BUFFER_FLUSH(ah);
DISABLE_REGWRITE_BUFFER(ah);
}
static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
{
struct ath_common *common = ath9k_hw_common(ah);
struct ath_nf_limits *limit;
int i;
if (IS_CHAN_2GHZ(ah->curchan))
limit = &ah->nf_2g;
else
limit = &ah->nf_5g;
for (i = 0; i < NUM_NF_READINGS; i++) {
if (!nf[i])
continue;
ath_print(common, ATH_DBG_CALIBRATE,
"NF calibrated [%s] [chain %d] is %d\n",
(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
if (nf[i] > limit->max) {
ath_print(common, ATH_DBG_CALIBRATE,
"NF[%d] (%d) > MAX (%d), correcting to MAX",
i, nf[i], limit->max);
nf[i] = limit->max;
} else if (nf[i] < limit->min) {
ath_print(common, ATH_DBG_CALIBRATE,
"NF[%d] (%d) < MIN (%d), correcting to NOM",
i, nf[i], limit->min);
nf[i] = limit->nominal;
}
}
}
bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
{
struct ath_common *common = ath9k_hw_common(ah);
int16_t nf, nfThresh;
int16_t nfarray[NUM_NF_READINGS] = { 0 };
struct ath9k_nfcal_hist *h;
struct ieee80211_channel *c = chan->chan;
struct ath9k_hw_cal_data *caldata = ah->caldata;
if (!caldata)
return false;
chan->channelFlags &= (~CHANNEL_CW_INT);
if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
ath_print(common, ATH_DBG_CALIBRATE,
"NF did not complete in calibration window\n");
nf = 0;
caldata->rawNoiseFloor = nf;
return false;
} else {
ath9k_hw_do_getnf(ah, nfarray);
ath9k_hw_nf_sanitize(ah, nfarray);
nf = nfarray[0];
if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
&& nf > nfThresh) {
ath_print(common, ATH_DBG_CALIBRATE,
"noise floor failed detected; "
"detected %d, threshold %d\n",
nf, nfThresh);
chan->channelFlags |= CHANNEL_CW_INT;
}
}
h = caldata->nfCalHist;
caldata->nfcal_pending = false;
ath9k_hw_update_nfcal_hist_buffer(h, nfarray);
caldata->rawNoiseFloor = h[0].privNF;
return true;
}
void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
struct ath9k_channel *chan)
{
struct ath9k_nfcal_hist *h;
s16 default_nf;
int i, j;
if (!ah->caldata)
return;
h = ah->caldata->nfCalHist;
default_nf = ath9k_hw_get_default_nf(ah, chan);
for (i = 0; i < NUM_NF_READINGS; i++) {
h[i].currIndex = 0;
h[i].privNF = default_nf;
h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++) {
h[i].nfCalBuffer[j] = default_nf;
}
}
}
s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan)
{
if (!ah->caldata || !ah->caldata->rawNoiseFloor)
return ath9k_hw_get_default_nf(ah, chan);
return ah->caldata->rawNoiseFloor;
}
EXPORT_SYMBOL(ath9k_hw_getchan_noise);