From e5e2647fd6ceef2cdc479954b84517535eb7febd Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Wed, 14 Oct 2009 14:16:30 -0400 Subject: ath5k: use noise calibration from madwifi hal This updates ath5k to calibrate the noise floor similar to the way it is done in the madwifi hal and ath9k. Of note: - we start NF measurement at the same time as AGC calibration, but do not actually read the value until the periodic (long) calibration - we keep a history of the last few values read and write the median back to the hardware for CCA - we do not complain if NF calibration isn't complete, instead we keep the last read value. Signed-off-by: Bob Copeland Acked-by: Nick Kossifidis Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath5k/phy.c | 185 ++++++++++++++++++++++++----------- 1 file changed, 128 insertions(+), 57 deletions(-) (limited to 'drivers/net/wireless/ath/ath5k/phy.c') diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c index 1a039f2bd73..895990751d3 100644 --- a/drivers/net/wireless/ath/ath5k/phy.c +++ b/drivers/net/wireless/ath/ath5k/phy.c @@ -1124,77 +1124,148 @@ ath5k_hw_calibration_poll(struct ath5k_hw *ah) ah->ah_swi_mask = AR5K_SWI_FULL_CALIBRATION; AR5K_REG_ENABLE_BITS(ah, AR5K_CR, AR5K_CR_SWI); } +} +static int sign_extend(int val, const int nbits) +{ + int order = BIT(nbits-1); + return (val ^ order) - order; } -/** - * ath5k_hw_noise_floor_calibration - perform PHY noise floor calibration - * - * @ah: struct ath5k_hw pointer we are operating on - * @freq: the channel frequency, just used for error logging - * - * This function performs a noise floor calibration of the PHY and waits for - * it to complete. Then the noise floor value is compared to some maximum - * noise floor we consider valid. - * - * Note that this is different from what the madwifi HAL does: it reads the - * noise floor and afterwards initiates the calibration. Since the noise floor - * calibration can take some time to finish, depending on the current channel - * use, that avoids the occasional timeout warnings we are seeing now. - * - * See the following link for an Atheros patent on noise floor calibration: - * http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL \ - * &p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7245893.PN.&OS=PN/7 +static s32 ath5k_hw_read_measured_noise_floor(struct ath5k_hw *ah) +{ + s32 val; + + val = ath5k_hw_reg_read(ah, AR5K_PHY_NF); + return sign_extend(AR5K_REG_MS(val, AR5K_PHY_NF_MINCCA_PWR), 9); +} + +void ath5k_hw_init_nfcal_hist(struct ath5k_hw *ah) +{ + int i; + + ah->ah_nfcal_hist.index = 0; + for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++) + ah->ah_nfcal_hist.nfval[i] = AR5K_TUNE_CCA_MAX_GOOD_VALUE; +} + +static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor) +{ + struct ath5k_nfcal_hist *hist = &ah->ah_nfcal_hist; + hist->index = (hist->index + 1) & (ATH5K_NF_CAL_HIST_MAX-1); + hist->nfval[hist->index] = noise_floor; +} + +static s16 ath5k_hw_get_median_noise_floor(struct ath5k_hw *ah) +{ + s16 sort[ATH5K_NF_CAL_HIST_MAX]; + s16 tmp; + int i, j; + + memcpy(sort, ah->ah_nfcal_hist.nfval, sizeof(sort)); + for (i = 0; i < ATH5K_NF_CAL_HIST_MAX - 1; i++) { + for (j = 1; j < ATH5K_NF_CAL_HIST_MAX - i; j++) { + if (sort[j] > sort[j-1]) { + tmp = sort[j]; + sort[j] = sort[j-1]; + sort[j-1] = tmp; + } + } + } + for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++) { + ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE, + "cal %d:%d\n", i, sort[i]); + } + return sort[(ATH5K_NF_CAL_HIST_MAX-1) / 2]; +} + +/* + * When we tell the hardware to perform a noise floor calibration + * by setting the AR5K_PHY_AGCCTL_NF bit, it will periodically + * sample-and-hold the minimum noise level seen at the antennas. + * This value is then stored in a ring buffer of recently measured + * noise floor values so we have a moving window of the last few + * samples. * - * XXX: Since during noise floor calibration antennas are detached according to - * the patent, we should stop tx queues here. + * The median of the values in the history is then loaded into the + * hardware for its own use for RSSI and CCA measurements. */ -int -ath5k_hw_noise_floor_calibration(struct ath5k_hw *ah, short freq) +void ath5k_hw_update_noise_floor(struct ath5k_hw *ah) { - int ret; - unsigned int i; - s32 noise_floor; + struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom; + u32 val; + s16 nf, threshold; + u8 ee_mode; - /* - * Enable noise floor calibration - */ - AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL, - AR5K_PHY_AGCCTL_NF); + /* keep last value if calibration hasn't completed */ + if (ath5k_hw_reg_read(ah, AR5K_PHY_AGCCTL) & AR5K_PHY_AGCCTL_NF) { + ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE, + "NF did not complete in calibration window\n"); - ret = ath5k_hw_register_timeout(ah, AR5K_PHY_AGCCTL, - AR5K_PHY_AGCCTL_NF, 0, false); - if (ret) { - ATH5K_ERR(ah->ah_sc, - "noise floor calibration timeout (%uMHz)\n", freq); - return -EAGAIN; + return; } - /* Wait until the noise floor is calibrated and read the value */ - for (i = 20; i > 0; i--) { - mdelay(1); - noise_floor = ath5k_hw_reg_read(ah, AR5K_PHY_NF); - noise_floor = AR5K_PHY_NF_RVAL(noise_floor); - if (noise_floor & AR5K_PHY_NF_ACTIVE) { - noise_floor = AR5K_PHY_NF_AVAL(noise_floor); - - if (noise_floor <= AR5K_TUNE_NOISE_FLOOR) - break; - } + switch (ah->ah_current_channel->hw_value & CHANNEL_MODES) { + case CHANNEL_A: + case CHANNEL_T: + case CHANNEL_XR: + ee_mode = AR5K_EEPROM_MODE_11A; + break; + case CHANNEL_G: + case CHANNEL_TG: + ee_mode = AR5K_EEPROM_MODE_11G; + break; + default: + case CHANNEL_B: + ee_mode = AR5K_EEPROM_MODE_11B; + break; } - ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_CALIBRATE, - "noise floor %d\n", noise_floor); - if (noise_floor > AR5K_TUNE_NOISE_FLOOR) { - ATH5K_ERR(ah->ah_sc, - "noise floor calibration failed (%uMHz)\n", freq); - return -EAGAIN; + /* completed NF calibration, test threshold */ + nf = ath5k_hw_read_measured_noise_floor(ah); + threshold = ee->ee_noise_floor_thr[ee_mode]; + + if (nf > threshold) { + ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE, + "noise floor failure detected; " + "read %d, threshold %d\n", + nf, threshold); + + nf = AR5K_TUNE_CCA_MAX_GOOD_VALUE; } - ah->ah_noise_floor = noise_floor; + ath5k_hw_update_nfcal_hist(ah, nf); + nf = ath5k_hw_get_median_noise_floor(ah); - return 0; + /* load noise floor (in .5 dBm) so the hardware will use it */ + val = ath5k_hw_reg_read(ah, AR5K_PHY_NF) & ~AR5K_PHY_NF_M; + val |= (nf * 2) & AR5K_PHY_NF_M; + ath5k_hw_reg_write(ah, val, AR5K_PHY_NF); + + AR5K_REG_MASKED_BITS(ah, AR5K_PHY_AGCCTL, AR5K_PHY_AGCCTL_NF, + ~(AR5K_PHY_AGCCTL_NF_EN | AR5K_PHY_AGCCTL_NF_NOUPDATE)); + + ath5k_hw_register_timeout(ah, AR5K_PHY_AGCCTL, AR5K_PHY_AGCCTL_NF, + 0, false); + + /* + * Load a high max CCA Power value (-50 dBm in .5 dBm units) + * so that we're not capped by the median we just loaded. + * This will be used as the initial value for the next noise + * floor calibration. + */ + val = (val & ~AR5K_PHY_NF_M) | ((-50 * 2) & AR5K_PHY_NF_M); + ath5k_hw_reg_write(ah, val, AR5K_PHY_NF); + AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL, + AR5K_PHY_AGCCTL_NF_EN | + AR5K_PHY_AGCCTL_NF_NOUPDATE | + AR5K_PHY_AGCCTL_NF); + + ah->ah_noise_floor = nf; + + ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_CALIBRATE, + "noise floor calibrated: %d\n", nf); } /* @@ -1287,7 +1358,7 @@ static int ath5k_hw_rf5110_calibrate(struct ath5k_hw *ah, return ret; } - ath5k_hw_noise_floor_calibration(ah, channel->center_freq); + ath5k_hw_update_noise_floor(ah); /* * Re-enable RX/TX and beacons @@ -1360,7 +1431,7 @@ done: * since noise floor calibration interrupts rx path while I/Q * calibration doesn't. We don't need to run noise floor calibration * as often as I/Q calibration.*/ - ath5k_hw_noise_floor_calibration(ah, channel->center_freq); + ath5k_hw_update_noise_floor(ah); /* Initiate a gain_F calibration */ ath5k_hw_request_rfgain_probe(ah); -- cgit v1.2.3-70-g09d2 From 2eb2fa67e5462a36e98172fb92c78bc405b3035f Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Mon, 16 Nov 2009 08:30:29 -0500 Subject: ath5k: allow setting txpower to 0 As a holdover from earlier code when we used to set the power limit to '0' after a reset to configure the default transmit power, ath5k interprets txpower=0 as 12.5 dBm. Fix that by just passing 0 through. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=14567 Cc: stable@kernel.org Reported-by: Daniel Folkers Tested-by: Daniel Folkers Signed-off-by: Bob Copeland Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath5k/phy.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/net/wireless/ath/ath5k/phy.c') diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c index 895990751d3..721ec5ee381 100644 --- a/drivers/net/wireless/ath/ath5k/phy.c +++ b/drivers/net/wireless/ath/ath5k/phy.c @@ -3025,8 +3025,6 @@ ath5k_hw_txpower(struct ath5k_hw *ah, struct ieee80211_channel *channel, ATH5K_ERR(ah->ah_sc, "invalid tx power: %u\n", txpower); return -EINVAL; } - if (txpower == 0) - txpower = AR5K_TUNE_DEFAULT_TXPOWER; /* Reset TX power values */ memset(&ah->ah_txpower, 0, sizeof(ah->ah_txpower)); -- cgit v1.2.3-70-g09d2 From f1cf2dbd0f798b71b1590e7aca6647f2caef1649 Mon Sep 17 00:00:00 2001 From: Lukáš Turek <8an@praha12.net> Date: Thu, 19 Nov 2009 23:02:02 +0100 Subject: ath5k: Fix I/Q calibration The sign of correction coefficients was lost in the calculations, which caused high packetloss in 802.11a mode after the results were applied. Fixed by removing unneccesary and broken AND with a bit mask. Signed-off-by: Lukas Turek <8an@praha12.net> Acked-by: Nick Kossifidis Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath5k/phy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/wireless/ath/ath5k/phy.c') diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c index 721ec5ee381..bbfdcd5e7cb 100644 --- a/drivers/net/wireless/ath/ath5k/phy.c +++ b/drivers/net/wireless/ath/ath5k/phy.c @@ -1399,7 +1399,7 @@ static int ath5k_hw_rf511x_calibrate(struct ath5k_hw *ah, if (i_coffd == 0 || q_coffd == 0) goto done; - i_coff = ((-iq_corr) / i_coffd) & 0x3f; + i_coff = ((-iq_corr) / i_coffd); /* Boundary check */ if (i_coff > 31) @@ -1407,7 +1407,7 @@ static int ath5k_hw_rf511x_calibrate(struct ath5k_hw *ah, if (i_coff < -32) i_coff = -32; - q_coff = (((s32)i_pwr / q_coffd) - 128) & 0x1f; + q_coff = (((s32)i_pwr / q_coffd) - 128); /* Boundary check */ if (q_coff > 15) -- cgit v1.2.3-70-g09d2