diff mbox series

[v2] ath10k: Per-chain rssi should sum the secondary channels

Message ID 20191217183343.25585-1-greearb@candelatech.com (mailing list archive)
State RFC
Delegated to: Kalle Valo
Headers show
Series [v2] ath10k: Per-chain rssi should sum the secondary channels | expand

Commit Message

Ben Greear Dec. 17, 2019, 6:33 p.m. UTC 
From: Ben Greear <greearb@candelatech.com>

This makes per-chain RSSI be more consistent between HT20, HT40, HT80.
Instead of doing precise log math for adding dbm, I did a rough estimate,
it seems to work good enough.

Tested on ath10k-ct 9984 firmware.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---

v2:  Should fix wave-1 rssi measurement (Thanks Sebastian)
     Add comments (Thanks Justin)
     Patch applies against upstream Linux ath10k driver

 drivers/net/wireless/ath/ath10k/htt_rx.c  | 75 +++++++++++++++++++++--
 drivers/net/wireless/ath/ath10k/rx_desc.h |  3 +-
 2 files changed, 73 insertions(+), 5 deletions(-)

Comments

Kalle Valo Dec. 21, 2020, 6:30 p.m. UTC | #1 
greearb@candelatech.com wrote:

> From: Ben Greear <greearb@candelatech.com>
> 
> This makes per-chain RSSI be more consistent between HT20, HT40, HT80.
> Instead of doing precise log math for adding dbm, I did a rough estimate,
> it seems to work good enough.
> 
> Tested on ath10k-ct 9984 firmware.
> 
> Signed-off-by: Ben Greear <greearb@candelatech.com>

Commented out code etc so I assume this is an RFC. Has anyone tested
this with upstream firmware?

Patch set to RFC.
Ben Greear Dec. 21, 2020, 10:21 p.m. UTC | #2 
On 12/21/20 10:30 AM, Kalle Valo wrote:
> greearb@candelatech.com wrote:
> 
>> From: Ben Greear <greearb@candelatech.com>
>>
>> This makes per-chain RSSI be more consistent between HT20, HT40, HT80.
>> Instead of doing precise log math for adding dbm, I did a rough estimate,
>> it seems to work good enough.
>>
>> Tested on ath10k-ct 9984 firmware.
>>
>> Signed-off-by: Ben Greear <greearb@candelatech.com>
> 
> Commented out code etc so I assume this is an RFC. Has anyone tested
> this with upstream firmware?

I probably tweaked this patch since sending.  my wave-1 didn't work with this approach,
and in the end, to get a valid RSSI, I ended up reading the
per-chain noise-floor periodically and storing that so I could use proper noise-floor
instead of just -95.  I am not sure upstream firmware can support that, so probably
not worth adding just the sum logic unless someone can figure out how to get the noise
floor out of the firmware...

Thanks,
Ben
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index d95b63f133ab..1227c9a83e47 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1149,6 +1149,48 @@  static bool ath10k_htt_rx_h_channel(struct ath10k *ar,
 	return true;
 }
 
+static int ath10k_sum_sigs_2(int a, int b) {
+	int diff;
+
+	/* 0x80 means value-is-not-set */
+	if (b == 0x80)
+		return a;
+
+	if (a >= b) {
+		/* a is largest value, add to it. */
+		diff = a - b;
+		if (diff == 0)
+			return a + 3;
+		else if (diff == 1)
+			return a + 2;
+		else if (diff == 2)
+			return a + 1;
+		return a;
+	}
+	else {
+		/* b is largest value, add to it. */
+		diff = b - a;
+		if (diff == 0)
+			return b + 3;
+		else if (diff == 1)
+			return b + 2;
+		else if (diff == 2)
+			return b + 1;
+		return b;
+	}
+}
+
+static int ath10k_sum_sigs(int p20, int e20, int e40, int e80) {
+	/* Hacky attempt at summing dbm without resorting to log(10) business */
+	/* 0x80 means value-is-not-set */
+	if (e40 != 0x80) {
+		return ath10k_sum_sigs_2(ath10k_sum_sigs_2(p20, e20), ath10k_sum_sigs_2(e40, e80));
+	}
+	else {
+		return ath10k_sum_sigs_2(p20, e20);
+	}
+}
+
 static void ath10k_htt_rx_h_signal(struct ath10k *ar,
 				   struct ieee80211_rx_status *status,
 				   struct htt_rx_desc *rxd)
@@ -1159,16 +1201,41 @@  static void ath10k_htt_rx_h_signal(struct ath10k *ar,
 		status->chains &= ~BIT(i);
 
 		if (rxd->ppdu_start.rssi_chains[i].pri20_mhz != 0x80) {
-			status->chain_signal[i] = ATH10K_DEFAULT_NOISE_FLOOR +
-				rxd->ppdu_start.rssi_chains[i].pri20_mhz;
+			status->chain_signal[i] = ATH10K_DEFAULT_NOISE_FLOOR
+				+ ath10k_sum_sigs(rxd->ppdu_start.rssi_chains[i].pri20_mhz,
+						  rxd->ppdu_start.rssi_chains[i].ext20_mhz,
+						  rxd->ppdu_start.rssi_chains[i].ext40_mhz,
+						  rxd->ppdu_start.rssi_chains[i].ext80_mhz);
+			/* ath10k_warn(ar, "rx-h-sig, chain[%i] pri20: %d ext20: %d  ext40: %d  ext80: %d\n",
+			 *	    i, rxd->ppdu_start.rssi_chains[i].pri20_mhz,
+			 *          rxd->ppdu_start.rssi_chains[i].ext20_mhz,
+			 *	    rxd->ppdu_start.rssi_chains[i].ext40_mhz,
+			 *          rxd->ppdu_start.rssi_chains[i].ext80_mhz);
+			 */
 
 			status->chains |= BIT(i);
 		}
 	}
 
 	/* FIXME: Get real NF */
-	status->signal = ATH10K_DEFAULT_NOISE_FLOOR +
-			 rxd->ppdu_start.rssi_comb;
+	/* 0x80 means value-is-not-set on wave-2 firmware.
+	 * For wave-2 firmware, value is not defined and is set to zero. */
+	if (rxd->ppdu_start.rssi_comb_ht &&
+	    (rxd->ppdu_start.rssi_comb_ht != 0x80)) {
+		status->signal = ATH10K_DEFAULT_NOISE_FLOOR +
+			rxd->ppdu_start.rssi_comb_ht;
+	}
+	else {
+		status->signal = ATH10K_DEFAULT_NOISE_FLOOR +
+			rxd->ppdu_start.rssi_comb;
+	}
+
+	/* ath10k_warn(ar, "rx-h-sig, signal: %d  chains: 0x%x  chain[0]: %d  chain[1]: %d  chain[2]: %d chain[3]: %d\n",
+	 *	    status->signal, status->chains, status->chain_signal[0],
+	 *	    status->chain_signal[1], status->chain_signal[2],
+	 *          status->chain_signal[3]);
+	 */
+
 	status->flag &= ~RX_FLAG_NO_SIGNAL_VAL;
 }
 
diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h b/drivers/net/wireless/ath/ath10k/rx_desc.h
index dec1582005b9..661deb81027c 100644
--- a/drivers/net/wireless/ath/ath10k/rx_desc.h
+++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
@@ -726,7 +726,8 @@  struct rx_ppdu_start {
 		u8 ext80_mhz;
 	} rssi_chains[4];
 	u8 rssi_comb;
-	__le16 rsvd0;
+	u8 rsvd0; /* wave-2: first two bits are bandwidth, other 6 reserved */
+	u8 rssi_comb_ht; /* wave-2 only, wave-1 sets to zero */
 	u8 info0; /* %RX_PPDU_START_INFO0_ */
 	__le32 info1; /* %RX_PPDU_START_INFO1_ */
 	__le32 info2; /* %RX_PPDU_START_INFO2_ */