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From:   Max Krummenacher <max.oss.09@gmail.com>
To:     max.krummenacher@toradex.com,
        Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Paolo Abeni <pabeni@redhat.com>,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Subject: [PATCH v1] Revert "Bluetooth: core: Fix missing power_on work cancel on HCI close"
Date:   Tue, 14 Jun 2022 20:17:06 +0200
Message-Id: <20220614181706.26513-1-max.oss.09@gmail.com>
MIME-Version: 1.0
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From: Max Krummenacher <max.krummenacher@toradex.com>

This reverts commit ff7f2926114d3a50f5ffe461a9bce8d761748da5.

The commit ff7f2926114d ("Bluetooth: core: Fix missing power_on work
cancel on HCI close") introduced between v5.18 and v5.19-rc1 makes
going to suspend freeze. v5.19-rc2 is equally affected.

This has been seen on a Colibri iMX6ULL WB which has a Marvell 8997
based WiFi / Bluetooth module connected over SDIO.

With 'v5.18' or 'v5.19-rc1 with said commit reverted' a suspend/resume
cycle looks as follows and the device is functional after the resume:

root@imx6ull:~# rfkill
ID TYPE      DEVICE    SOFT      HARD
 0 bluetooth hci0   blocked unblocked
 1 wlan      phy0   blocked unblocked
root@imx6ull:~# echo enabled > /sys/class/tty/ttymxc0/power/wakeup
root@imx6ull:~# date;echo mem > /sys/power/state;date
Tue Jun 14 14:43:03 UTC 2022
[ 6393.464497] PM: suspend entry (deep)
[ 6393.529398] Filesystems sync: 0.064 seconds
[ 6393.594006] Freezing user space processes ... (elapsed 0.015 seconds) done.
[ 6393.610266] OOM killer disabled.
[ 6393.610285] Freezing remaining freezable tasks ... (elapsed 0.013 seconds) done.
[ 6393.623727] printk: Suspending console(s) (use no_console_suspend to debug)

~~ suspended until console initiates the resume

[ 6394.023552] fec 20b4000.ethernet eth0: Link is Down
[ 6394.049902] PM: suspend devices took 0.300 seconds
[ 6394.091654] Disabling non-boot CPUs ...
[ 6394.565896] PM: resume devices took 0.440 seconds
[ 6394.681350] OOM killer enabled.
[ 6394.681369] Restarting tasks ... done.
[ 6394.741157] random: crng reseeded on system resumption
[ 6394.813135] PM: suspend exit
Tue Jun 14 14:43:11 UTC 2022
[ 6396.403873] fec 20b4000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 6396.404347] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
root@imx6ull:~#

With 'v5.19-rc1' suspend freezes in the suspend phase, i.e. power
consumption is not lowered and no wakeup source initiates a wakup.

root@imx6ull:~# rfkill
ID TYPE      DEVICE    SOFT      HARD
 0 bluetooth hci0   blocked unblocked
 1 wlan      phy0   blocked unblocked
root@imx6ull:~# echo enabled > /sys/class/tty/ttymxc0/power/wakeup
root@imx6ull:~# date;echo mem > /sys/power/state;date
Tue Jun 14 12:40:38 UTC 2022
[  122.476333] PM: suspend entry (deep)
[  122.556012] Filesystems sync: 0.079 seconds

~~ no further kernel output

If one first unbinds the bluetooth device driver, suspend / resume works
as expected also with 'v5.19-rc1':

root@imx6ull:~# echo mmc1:0001:2 > /sys/bus/sdio/drivers/btmrvl_sdio/unbind
root@imx6ull:~# rfkill
ID TYPE DEVICE    SOFT      HARD
 1 wlan phy0   blocked unblocked
root@imx6ull:~# echo enabled > /sys/class/tty/ttymxc0/power/wakeup
root@imx6ull:~# date;echo mem > /sys/power/state;date
Tue Jun 14 14:59:26 UTC 2022
[  123.530310] PM: suspend entry (deep)
[  123.595432] Filesystems sync: 0.064 seconds
[  123.672478] Freezing user space processes ... (elapsed 0.028 seconds) done.
[  123.701848] OOM killer disabled.
[  123.701869] Freezing remaining freezable tasks ... (elapsed 0.007 seconds) done.
[  123.709993] printk: Suspending console(s) (use no_console_suspend to debug)
[  124.097772] fec 20b4000.ethernet eth0: Link is Down
[  124.124795] PM: suspend devices took 0.280 seconds
[  124.165893] Disabling non-boot CPUs ...
[  124.632959] PM: resume devices took 0.430 seconds
[  124.750164] OOM killer enabled.
[  124.750187] Restarting tasks ... done.
[  124.827899] random: crng reseeded on system resumption
[  124.923183] PM: suspend exit
Tue Jun 14 14:59:31 UTC 2022
[  127.520321] fec 20b4000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[  127.520514] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
root@imx6ull:~#

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>

---

 net/bluetooth/hci_core.c | 2 ++
 net/bluetooth/hci_sync.c | 1 -
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 59a5c1341c26..19df3905c5f8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2675,6 +2675,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 	list_del(&hdev->list);
 	write_unlock(&hci_dev_list_lock);
 
+	cancel_work_sync(&hdev->power_on);
+
 	hci_cmd_sync_clear(hdev);
 
 	if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 286d6767f017..1739e8cb3291 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4088,7 +4088,6 @@ int hci_dev_close_sync(struct hci_dev *hdev)
 
 	bt_dev_dbg(hdev, "");
 
-	cancel_work_sync(&hdev->power_on);
 	cancel_delayed_work(&hdev->power_off);
 	cancel_delayed_work(&hdev->ncmd_timer);
 
-- 
2.20.1