mac80211: rt2x00: fix MT7620 LNA gain and VCO-after-ALC

This should fix issues with bad RX as well as AP not coming up and/or
scanning failing.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

2 files changed, 88 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/021-01-rt2800-fix-LNA-gain-assignment-for-MT7620.patch b/package/kernel/mac80211/patches/021-01-rt2800-fix-LNA-gain-assignment-for-MT7620.patch
new file mode 100644
index 0000000..3270ea2
--- /dev/null
+++ b/package/kernel/mac80211/patches/021-01-rt2800-fix-LNA-gain-assignment-for-MT7620.patch
@@ -0,0 +1,54 @@
+From 0109238d62a99ea779a7e28e21868118e7b8d69d Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Mon, 10 Apr 2017 14:28:14 +0200
+Subject: [PATCH 1/2] rt2800: fix LNA gain assignment for MT7620
+To: Stanislaw Gruszka <sgruszka@redhat.com>
+Cc: Helmut Schaa <helmut.schaa@googlemail.com>,
+    linux-wireless@vger.kernel.org,
+    Kalle Valo <kvalo@codeaurora.org>
+
+The base value used for MT7620 differs from Rt5392 which resulted in
+quite bad RX signal quality. Fix this by using the correct base value as
+well as the LNA calibration values for HT20.
+
+Reported-by: Tom Psyborg <pozega.tomislav@gmail.com>
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/net/wireless/ralink/rt2x00/rt2800lib.c | 18 ++++++++++++++++--
+ 1 file changed, 16 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+index ba06ac2d876d..7135519a638c 100644
+--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
++++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+@@ -3806,11 +3806,25 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
+ 	}
+ 
+ 	if (rt2x00_rt(rt2x00dev, RT5592) || rt2x00_rt(rt2x00dev, RT6352)) {
++		reg = 0x10;
++		if (!conf_is_ht40(conf)) {
++			if (rt2x00_rt(rt2x00dev, RT6352) &&
++			    rt2x00_has_cap_external_lna_bg(rt2x00dev)) {
++				reg |= 0x5;
++			} else {
++				reg |= 0xa;
++			}
++		}
+ 		rt2800_bbp_write(rt2x00dev, 195, 141);
+-		rt2800_bbp_write(rt2x00dev, 196, conf_is_ht40(conf) ? 0x10 : 0x1a);
++		rt2800_bbp_write(rt2x00dev, 196, reg);
+ 
+ 		/* AGC init */
+-		reg = (rf->channel <= 14 ? 0x1c : 0x24) + 2 * rt2x00dev->lna_gain;
++		if (rt2x00_rt(rt2x00dev, RT6352))
++			reg = 0x04;
++		else
++			reg = rf->channel <= 14 ? 0x1c : 0x24;
++
++		reg += 2 * rt2x00dev->lna_gain;
+ 		rt2800_bbp_write_with_rx_chain(rt2x00dev, 66, reg);
+ 
+ 		rt2800_iq_calibrate(rt2x00dev, rf->channel);
+-- 
+2.12.2
+
diff --git a/package/kernel/mac80211/patches/021-02-rt2800-do-VCO-calibration-after-programming-ALC.patch b/package/kernel/mac80211/patches/021-02-rt2800-do-VCO-calibration-after-programming-ALC.patch
new file mode 100644
index 0000000..1dafb78
--- /dev/null
+++ b/package/kernel/mac80211/patches/021-02-rt2800-do-VCO-calibration-after-programming-ALC.patch
@@ -0,0 +1,34 @@
+From feb608c7986c14bab153f31f8e96f251072e6578 Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Mon, 10 Apr 2017 15:33:20 +0200
+Subject: [PATCH 2/2] rt2800: do VCO calibration after programming ALC
+To: Stanislaw Gruszka <sgruszka@redhat.com>
+Cc: Helmut Schaa <helmut.schaa@googlemail.com>,
+    linux-wireless@vger.kernel.org,
+    Kalle Valo <kvalo@codeaurora.org>
+
+Scanning fails if we don't do VCO calibration every time.
+The vendor driver duplicates the VCO calibration function into the
+channel switching logic, we can do the same with less duplication.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/net/wireless/ralink/rt2x00/rt2800lib.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+index 7135519a638c..870bf315f98b 100644
+--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
++++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+@@ -3407,6 +3407,8 @@ static void rt2800_config_alc(struct rt2x00_dev *rt2x00dev,
+ 			rt2800_rfcsr_write(rt2x00dev, 42, 0x5b);
+ 	}
+ 	rt2800_register_write(rt2x00dev, MAC_SYS_CTRL, mac_sys_ctrl);
++
++	rt2800_vco_calibration(rt2x00dev);
+ }
+ 
+ static void rt2800_bbp_write_with_rx_chain(struct rt2x00_dev *rt2x00dev,
+-- 
+2.12.2
+