From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>,
Alan Stern <stern@rowland.harvard.edu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
mathias.nyman@linux.intel.com, Thinh.Nguyen@synopsys.com,
rajatja@google.com, chris.chiu@canonical.com, andrew@lunn.ch,
linux-usb@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 076/116] usb: hub: Add delay for SuperSpeed hub resume to let links transit to U0
Date: Mon, 17 Jan 2022 21:39:27 -0500 [thread overview]
Message-ID: <20220118024007.1950576-76-sashal@kernel.org> (raw)
In-Reply-To: <20220118024007.1950576-1-sashal@kernel.org>
From: Kai-Heng Feng <kai.heng.feng@canonical.com>
[ Upstream commit 00558586382891540c59c9febc671062425a6e47 ]
When a new USB device gets plugged to nested hubs, the affected hub,
which connects to usb 2-1.4-port2, doesn't report there's any change,
hence the nested hubs go back to runtime suspend like nothing happened:
[ 281.032951] usb usb2: usb wakeup-resume
[ 281.032959] usb usb2: usb auto-resume
[ 281.032974] hub 2-0:1.0: hub_resume
[ 281.033011] usb usb2-port1: status 0263 change 0000
[ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.049797] usb 2-1: usb wakeup-resume
[ 281.069800] usb 2-1: Waited 0ms for CONNECT
[ 281.069810] usb 2-1: finish resume
[ 281.070026] hub 2-1:1.0: hub_resume
[ 281.070250] usb 2-1-port4: status 0203 change 0000
[ 281.070272] usb usb2-port1: resume, status 0
[ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[ 281.089813] usb 2-1.4: usb wakeup-resume
[ 281.109792] usb 2-1.4: Waited 0ms for CONNECT
[ 281.109801] usb 2-1.4: finish resume
[ 281.109991] hub 2-1.4:1.0: hub_resume
[ 281.110147] usb 2-1.4-port2: status 0263 change 0000
[ 281.110234] usb 2-1-port4: resume, status 0
[ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.110426] hub 2-1.4:1.0: hub_suspend
[ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1
[ 281.130998] hub 2-1:1.0: hub_suspend
[ 281.137788] usb 2-1: usb auto-suspend, wakeup 1
[ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.177828] usb 2-1: usb wakeup-resume
[ 281.197839] usb 2-1: Waited 0ms for CONNECT
[ 281.197850] usb 2-1: finish resume
[ 281.197984] hub 2-1:1.0: hub_resume
[ 281.198203] usb 2-1-port4: status 0203 change 0000
[ 281.198228] usb usb2-port1: resume, status 0
[ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[ 281.217835] usb 2-1.4: usb wakeup-resume
[ 281.237834] usb 2-1.4: Waited 0ms for CONNECT
[ 281.237845] usb 2-1.4: finish resume
[ 281.237990] hub 2-1.4:1.0: hub_resume
[ 281.238067] usb 2-1.4-port2: status 0263 change 0000
[ 281.238148] usb 2-1-port4: resume, status 0
[ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.238385] hub 2-1.4:1.0: hub_suspend
[ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1
[ 281.258076] hub 2-1:1.0: hub_suspend
[ 281.265744] usb 2-1: usb auto-suspend, wakeup 1
[ 281.285976] hub 2-0:1.0: hub_suspend
[ 281.285988] usb usb2: bus auto-suspend, wakeup 1
USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If
the link is in a non-U0 state, then the device must transition the link
to U0 prior to sending the remote wake message", but the hub only
transits the link to U0 after signaling remote wakeup.
So be more forgiving and use a 20ms delay to let the link transit to U0
for remote wakeup.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/core/hub.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 3f406519da58d..8af06a933e289 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1109,7 +1109,10 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
} else {
hub_power_on(hub, true);
}
- }
+ /* Give some time on remote wakeup to let links to transit to U0 */
+ } else if (hub_is_superspeed(hub->hdev))
+ msleep(20);
+
init2:
/*
--
2.34.1
prev parent reply other threads:[~2022-01-18 3:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220118024007.1950576-1-sashal@kernel.org>
2022-01-18 2:38 ` [PATCH AUTOSEL 5.10 016/116] usb: gadget: f_fs: Use stream_open() for endpoint files Sasha Levin
2022-01-18 2:38 ` [PATCH AUTOSEL 5.10 041/116] usb: uhci: add aspeed ast2600 uhci support Sasha Levin
2022-01-18 2:39 ` [PATCH AUTOSEL 5.10 049/116] thunderbolt: Runtime PM activate both ends of the device link Sasha Levin
2022-01-18 2:39 ` Sasha Levin [this message]
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