[PATCH AUTOSEL 4.14 13/20] wifi: rtl8xxxu: fix authentication timeout due to incorrect RCR value

[Sasha Levin]

From: Yun Lu <luyun@xxxxxxxxxx>

[ Upstream commit 20429444e653ee8242dfbf815c0c37866beb371b ]

When using rtl8192cu with rtl8xxxu driver to connect wifi, there is a
probability of failure, which shows "authentication with ... timed out".
Through debugging, it was found that the RCR register has been inexplicably
modified to an incorrect value, resulting in the nic not being able to
receive authenticated frames.

To fix this problem, add regrcr in rtl8xxxu_priv struct, and store
the RCR value every time the register is written, and use it the next
time the register need to be modified.

Signed-off-by: Yun Lu <luyun@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20230427020512.1221062-1-luyun_611@xxxxxxx
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230512012055.2990472-1-luyun_611@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h      | 1 +
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
index c1163f2a09251..1913b51c1e809 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
@@ -1268,6 +1268,7 @@ struct rtl8xxxu_priv {
 	u32 rege9c;
 	u32 regeb4;
 	u32 regebc;
+	u32 regrcr;
 	int next_mbox;
 	int nr_out_eps;
 
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 1c9f7e1f63cfd..bfd704b17a447 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -4051,6 +4051,7 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw)
 		RCR_ACCEPT_MGMT_FRAME | RCR_HTC_LOC_CTRL |
 		RCR_APPEND_PHYSTAT | RCR_APPEND_ICV | RCR_APPEND_MIC;
 	rtl8xxxu_write32(priv, REG_RCR, val32);
+	priv->regrcr = val32;
 
 	/*
 	 * Accept all multicast
@@ -5591,7 +5592,7 @@ static void rtl8xxxu_configure_filter(struct ieee80211_hw *hw,
 				      unsigned int *total_flags, u64 multicast)
 {
 	struct rtl8xxxu_priv *priv = hw->priv;
-	u32 rcr = rtl8xxxu_read32(priv, REG_RCR);
+	u32 rcr = priv->regrcr;
 
 	dev_dbg(&priv->udev->dev, "%s: changed_flags %08x, total_flags %08x\n",
 		__func__, changed_flags, *total_flags);
@@ -5637,6 +5638,7 @@ static void rtl8xxxu_configure_filter(struct ieee80211_hw *hw,
 	 */
 
 	rtl8xxxu_write32(priv, REG_RCR, rcr);
+	priv->regrcr = rcr;
 
 	*total_flags &= (FIF_ALLMULTI | FIF_FCSFAIL | FIF_BCN_PRBRESP_PROMISC |
 			 FIF_CONTROL | FIF_OTHER_BSS | FIF_PSPOLL |
-- 
2.39.2