From 748619220651a33c260ed6c0a7648e69324edd74 Mon Sep 17 00:00:00 2001 From: Ivo van Doorn Date: Sun, 11 Jul 2010 12:23:50 +0200 Subject: [PATCH] rt2x00: Convert AGC value from descriptor to RSSI (dBm) The RSSI values in the RXWI descriptor aren't true RSSI values. Instead they are more like the AGC values similar to rt61pci. And as such, it needs the same conversion before it can be passed to rt2x00lib/mac80211. This requires the struct queue_entry to be passed to rt2800_process_rxwi rather then the skb structure which is contained in the queue_entry. This is required to obtain the lna_gain information from the rt2x00_dev structure. This fixes connection problems when using wpa_supplicant which would try to connect to the worst AP's rather then the best ones. Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt2800.h | 2 +- drivers/net/wireless/rt2x00/rt2800lib.c | 57 ++++++++++++++++++++++--- drivers/net/wireless/rt2x00/rt2800lib.h | 2 +- drivers/net/wireless/rt2x00/rt2800pci.c | 2 +- drivers/net/wireless/rt2x00/rt2800usb.c | 2 +- 5 files changed, 55 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800.h b/drivers/net/wireless/rt2x00/rt2800.h index 3cda22931876..edd3734b8b32 100644 --- a/drivers/net/wireless/rt2x00/rt2800.h +++ b/drivers/net/wireless/rt2x00/rt2800.h @@ -74,7 +74,7 @@ * Signal information. * Default offset is required for RSSI <-> dBm conversion. */ -#define DEFAULT_RSSI_OFFSET 120 /* FIXME */ +#define DEFAULT_RSSI_OFFSET 120 /* * Register layout information. diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c index 9030eef2403d..255d089e87ea 100644 --- a/drivers/net/wireless/rt2x00/rt2800lib.c +++ b/drivers/net/wireless/rt2x00/rt2800lib.c @@ -325,9 +325,53 @@ void rt2800_write_txwi(__le32 *txwi, struct txentry_desc *txdesc) } EXPORT_SYMBOL_GPL(rt2800_write_txwi); -void rt2800_process_rxwi(struct sk_buff *skb, struct rxdone_entry_desc *rxdesc) +static int rt2800_agc_to_rssi(struct rt2x00_dev *rt2x00dev, int rxwi_w2) { - __le32 *rxwi = (__le32 *) skb->data; + int rssi0 = rt2x00_get_field32(rxwi_w2, RXWI_W2_RSSI0); + int rssi1 = rt2x00_get_field32(rxwi_w2, RXWI_W2_RSSI1); + int rssi2 = rt2x00_get_field32(rxwi_w2, RXWI_W2_RSSI2); + u16 eeprom; + u8 offset0; + u8 offset1; + u8 offset2; + + if (rt2x00dev->rx_status.band == IEEE80211_BAND_2GHZ) { + rt2x00_eeprom_read(rt2x00dev, EEPROM_RSSI_BG, &eeprom); + offset0 = rt2x00_get_field16(eeprom, EEPROM_RSSI_BG_OFFSET0); + offset1 = rt2x00_get_field16(eeprom, EEPROM_RSSI_BG_OFFSET1); + rt2x00_eeprom_read(rt2x00dev, EEPROM_RSSI_BG2, &eeprom); + offset2 = rt2x00_get_field16(eeprom, EEPROM_RSSI_BG2_OFFSET2); + } else { + rt2x00_eeprom_read(rt2x00dev, EEPROM_RSSI_A, &eeprom); + offset0 = rt2x00_get_field16(eeprom, EEPROM_RSSI_A_OFFSET0); + offset1 = rt2x00_get_field16(eeprom, EEPROM_RSSI_A_OFFSET1); + rt2x00_eeprom_read(rt2x00dev, EEPROM_RSSI_A2, &eeprom); + offset2 = rt2x00_get_field16(eeprom, EEPROM_RSSI_A2_OFFSET2); + } + + /* + * Convert the value from the descriptor into the RSSI value + * If the value in the descriptor is 0, it is considered invalid + * and the default (extremely low) rssi value is assumed + */ + rssi0 = (rssi0) ? (-12 - offset0 - rt2x00dev->lna_gain - rssi0) : -128; + rssi1 = (rssi1) ? (-12 - offset1 - rt2x00dev->lna_gain - rssi1) : -128; + rssi2 = (rssi2) ? (-12 - offset2 - rt2x00dev->lna_gain - rssi2) : -128; + + /* + * mac80211 only accepts a single RSSI value. Calculating the + * average doesn't deliver a fair answer either since -60:-60 would + * be considered equally good as -50:-70 while the second is the one + * which gives less energy... + */ + rssi0 = max(rssi0, rssi1); + return max(rssi0, rssi2); +} + +void rt2800_process_rxwi(struct queue_entry *entry, + struct rxdone_entry_desc *rxdesc) +{ + __le32 *rxwi = (__le32 *) entry->skb->data; u32 word; rt2x00_desc_read(rxwi, 0, &word); @@ -358,14 +402,15 @@ void rt2800_process_rxwi(struct sk_buff *skb, struct rxdone_entry_desc *rxdesc) rt2x00_desc_read(rxwi, 2, &word); - rxdesc->rssi = - (rt2x00_get_field32(word, RXWI_W2_RSSI0) + - rt2x00_get_field32(word, RXWI_W2_RSSI1)) / 2; + /* + * Convert descriptor AGC value to RSSI value. + */ + rxdesc->rssi = rt2800_agc_to_rssi(entry->queue->rt2x00dev, word); /* * Remove RXWI descriptor from start of buffer. */ - skb_pull(skb, RXWI_DESC_SIZE); + skb_pull(entry->skb, RXWI_DESC_SIZE); } EXPORT_SYMBOL_GPL(rt2800_process_rxwi); diff --git a/drivers/net/wireless/rt2x00/rt2800lib.h b/drivers/net/wireless/rt2x00/rt2800lib.h index 8313dbf441a5..eb3a4f50a363 100644 --- a/drivers/net/wireless/rt2x00/rt2800lib.h +++ b/drivers/net/wireless/rt2x00/rt2800lib.h @@ -121,7 +121,7 @@ void rt2800_mcu_request(struct rt2x00_dev *rt2x00dev, const u8 arg0, const u8 arg1); void rt2800_write_txwi(__le32 *txwi, struct txentry_desc *txdesc); -void rt2800_process_rxwi(struct sk_buff *skb, struct rxdone_entry_desc *txdesc); +void rt2800_process_rxwi(struct queue_entry *entry, struct rxdone_entry_desc *txdesc); void rt2800_write_beacon(struct queue_entry *entry, struct txentry_desc *txdesc); diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c index 6f11760117da..faf71e2aeb64 100644 --- a/drivers/net/wireless/rt2x00/rt2800pci.c +++ b/drivers/net/wireless/rt2x00/rt2800pci.c @@ -805,7 +805,7 @@ static void rt2800pci_fill_rxdone(struct queue_entry *entry, /* * Process the RXWI structure that is at the start of the buffer. */ - rt2800_process_rxwi(entry->skb, rxdesc); + rt2800_process_rxwi(entry, rxdesc); /* * Set RX IDX in register to inform hardware that we have handled diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c index 4f85f7b42441..f2cd37e5aea8 100644 --- a/drivers/net/wireless/rt2x00/rt2800usb.c +++ b/drivers/net/wireless/rt2x00/rt2800usb.c @@ -563,7 +563,7 @@ static void rt2800usb_fill_rxdone(struct queue_entry *entry, /* * Process the RXWI structure. */ - rt2800_process_rxwi(entry->skb, rxdesc); + rt2800_process_rxwi(entry, rxdesc); } /*