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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Chris Chiu <chiu@endlessm.com>,
        Jes Sorensen <Jes.Sorensen@gmail.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 040/171] rtl8xxxu: fix RTL8723BU connection failure issue after warm reboot
Date:   Thu,  2 Jan 2020 23:06:11 +0100
Message-Id: <20200102220552.562528125@linuxfoundation.org>
In-Reply-To: <20200102220546.960200039@linuxfoundation.org>
References: <20200102220546.960200039@linuxfoundation.org>
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From: Chris Chiu <chiu@endlessm.com>

[ Upstream commit 0eeb91ade90ce06d2fa1e2fcb55e3316b64c203c ]

The RTL8723BU has problems connecting to AP after each warm reboot.
Sometimes it returns no scan result, and in most cases, it fails
the authentication for unknown reason. However, it works totally
fine after cold reboot.

Compare the value of register SYS_CR and SYS_CLK_MAC_CLK_ENABLE
for cold reboot and warm reboot, the registers imply that the MAC
is already powered and thus some procedures are skipped during
driver initialization. Double checked the vendor driver, it reads
the SYS_CR and SYS_CLK_MAC_CLK_ENABLE also but doesn't skip any
during initialization based on them. This commit only tells the
RTL8723BU to do full initialization without checking MAC status.

Signed-off-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h       | 1 +
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c | 1 +
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c  | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
index 08d587a342d3..9143b173935d 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
@@ -1348,6 +1348,7 @@ struct rtl8xxxu_fileops {
 	u8 has_s0s1:1;
 	u8 has_tx_report:1;
 	u8 gen2_thermal_meter:1;
+	u8 needs_full_init:1;
 	u32 adda_1t_init;
 	u32 adda_1t_path_on;
 	u32 adda_2t_path_on_a;
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
index 02b8ddd98a95..f51ee88d692b 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
@@ -1673,6 +1673,7 @@ struct rtl8xxxu_fileops rtl8723bu_fops = {
 	.has_s0s1 = 1,
 	.has_tx_report = 1,
 	.gen2_thermal_meter = 1,
+	.needs_full_init = 1,
 	.adda_1t_init = 0x01c00014,
 	.adda_1t_path_on = 0x01c00014,
 	.adda_2t_path_on_a = 0x01c00014,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index e78545d4add3..6d34d442294a 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -3905,6 +3905,9 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
 	else
 		macpower = true;
 
+	if (fops->needs_full_init)
+		macpower = false;
+
 	ret = fops->power_on(priv);
 	if (ret < 0) {
 		dev_warn(dev, "%s: Failed power on\n", __func__);
-- 
2.20.1