RE: wifi: rtw88: 8821CU hangs after some number of power-off/on cycles

[Ping-Ke Shih <pkshih@realtek.com>]

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Marcin Ślusarz <marcin.slusarz@gmail.com> wrote:
> wt., 28 maj 2024 o 05:52 Ping-Ke Shih <pkshih@realtek.com> napisał(a):
> >
> > Marcin Ślusarz <marcin.slusarz@gmail.com> wrote:
> > >
> > > I found out that the reason for those hangs is a power-off+on sequence that's
> > > triggered by the above steps.
> >
> > To avoid power-off/on sequence once device becomes idle, I would like to add
> > a ips_disabled helper. Please revert your changes and apply my attached patch.
> 
> My first attempt was very similar, and it fixed some cases but not all of them.
> 
> This is due to the existence of a second source of power-offs - rtw_ops_stop,
> which is called, e.g., on downing the interface (ifconfig wlan0 down).

Please try attached v2 patch. I would like to have an explicit helper
(i.e. always_power_on in v2) to have this fix, so days later people can be easy
to understand how it works. Not prefer adjusting existing flags to implicitly
have behavior you want. 



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From 715a7e758949595646e9134869667dc5a0437c3e Mon Sep 17 00:00:00 2001
From: Ping-Ke Shih <pkshih@realtek.com>
Date: Tue, 28 May 2024 11:48:13 +0800
Subject: [PATCH v2] wifi: rtw88: 8821cu: keep power on always for 8821CU
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This chip fails to reliably wake up from power off.

Change-Id: I295de3c71fe91af37e8cc39b70728a8ba7e94b2f
Reported-by: Marcin Ślusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 mac80211.c |  2 +-
 main.c     | 10 ++++++++--
 main.h     |  2 ++
 ps.c       |  5 ++++-
 ps.h       |  2 +-
 usb.c      |  3 +++
 wow.c      |  2 +-
 7 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/mac80211.c b/mac80211.c
index 78078d65c88f..5202ba74c20a 100644
--- a/mac80211.c
+++ b/mac80211.c
@@ -99,7 +99,7 @@ static int rtw_ops_config(struct ieee80211_hw *hw, u32 changed)
 	if ((changed & IEEE80211_CONF_CHANGE_IDLE) &&
 	    (hw->conf.flags & IEEE80211_CONF_IDLE) &&
 	    !test_bit(RTW_FLAG_SCANNING, rtwdev->flags))
-		rtw_enter_ips(rtwdev);
+		rtw_enter_ips(rtwdev, false);
 
 out:
 	mutex_unlock(&rtwdev->mutex);
diff --git a/main.c b/main.c
index 567f9d4373c4..90d18b338a12 100644
--- a/main.c
+++ b/main.c
@@ -306,7 +306,7 @@ static void rtw_ips_work(struct work_struct *work)
 
 	mutex_lock(&rtwdev->mutex);
 	if (rtwdev->hw->conf.flags & IEEE80211_CONF_IDLE)
-		rtw_enter_ips(rtwdev);
+		rtw_enter_ips(rtwdev, false);
 	mutex_unlock(&rtwdev->mutex);
 }
 
@@ -660,7 +660,7 @@ free:
 	rtw_iterate_stas_atomic(rtwdev, rtw_reset_sta_iter, rtwdev);
 	rtw_iterate_vifs_atomic(rtwdev, rtw_reset_vif_iter, rtwdev);
 	bitmap_zero(rtwdev->hw_port, RTW_PORT_NUM);
-	rtw_enter_ips(rtwdev);
+	rtw_enter_ips(rtwdev, true);
 }
 
 static void rtw_fw_recovery_work(struct work_struct *work)
@@ -1375,6 +1375,9 @@ static int rtw_power_on(struct rtw_dev *rtwdev)
 	bool wifi_only;
 	int ret;
 
+	if (rtwdev->always_power_on && test_bit(RTW_FLAG_POWERON, rtwdev->flags))
+		return 0;
+
 	ret = rtw_hci_setup(rtwdev);
 	if (ret) {
 		rtw_err(rtwdev, "failed to setup hci\n");
@@ -1525,6 +1528,9 @@ int rtw_core_start(struct rtw_dev *rtwdev)
 
 static void rtw_power_off(struct rtw_dev *rtwdev)
 {
+	if (rtwdev->always_power_on)
+		return;
+
 	rtw_hci_stop(rtwdev);
 	rtw_coex_power_off_setting(rtwdev);
 	rtw_mac_power_off(rtwdev);
diff --git a/main.h b/main.h
index d9afb585d423..e1c316bd7018 100644
--- a/main.h
+++ b/main.h
@@ -2283,6 +2283,8 @@ struct rtw_dev {
 	bool beacon_loss;
 	struct completion lps_leave_check;
 
+	bool always_power_on;
+
 	struct dentry *debugfs;
 
 	u8 sta_cnt;
diff --git a/ps.c b/ps.c
index b171e62d2d57..65223751fe2c 100644
--- a/ps.c
+++ b/ps.c
@@ -24,8 +24,11 @@ static int rtw_ips_pwr_up(struct rtw_dev *rtwdev)
 	return ret;
 }
 
-int rtw_enter_ips(struct rtw_dev *rtwdev)
+int rtw_enter_ips(struct rtw_dev *rtwdev, bool force)
 {
+	if (!force && rtwdev->always_power_on)
+		return 0;
+
 	if (!test_bit(RTW_FLAG_POWERON, rtwdev->flags))
 		return 0;
 
diff --git a/ps.h b/ps.h
index 5ae83d2526cf..92057d01cbec 100644
--- a/ps.h
+++ b/ps.h
@@ -15,7 +15,7 @@
 #define LEAVE_LPS_TRY_CNT	5
 #define LEAVE_LPS_TIMEOUT	msecs_to_jiffies(100)
 
-int rtw_enter_ips(struct rtw_dev *rtwdev);
+int rtw_enter_ips(struct rtw_dev *rtwdev, bool force);
 int rtw_leave_ips(struct rtw_dev *rtwdev);
 
 void rtw_power_mode_change(struct rtw_dev *rtwdev, bool enter);
diff --git a/usb.c b/usb.c
index a0188511099a..22742fe81b9a 100644
--- a/usb.c
+++ b/usb.c
@@ -854,6 +854,9 @@ int rtw_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	rtwdev->hci.ops = &rtw_usb_ops;
 	rtwdev->hci.type = RTW_HCI_TYPE_USB;
 
+	if (rtwdev->chip->id == RTW_CHIP_TYPE_8821C)
+		rtwdev->always_power_on = true;
+
 	rtwusb = rtw_get_usb_priv(rtwdev);
 	rtwusb->rtwdev = rtwdev;
 
diff --git a/wow.c b/wow.c
index c86cfc47361a..2163e1dab630 100644
--- a/wow.c
+++ b/wow.c
@@ -677,7 +677,7 @@ static int rtw_wow_restore_ps(struct rtw_dev *rtwdev)
 	int ret = 0;
 
 	if (rtw_wow_no_link(rtwdev) && rtwdev->wow.ips_enabled)
-		ret = rtw_enter_ips(rtwdev);
+		ret = rtw_enter_ips(rtwdev, false);
 
 	return ret;
 }
-- 
2.25.1