[lkml]   [2019]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH AUTOSEL 4.19 035/100] usb: handle warm-reset port requests on hub resume
From: Jan-Marek Glogowski <>

[ Upstream commit 4fdc1790e6a9ef22399c6bc6e63b80f4609f3b7e ]

On plug-in of my USB-C device, its USB_SS_PORT_LS_SS_INACTIVE
link state bit is set. Greping all the kernel for this bit shows
that the port status requests a warm-reset this way.

This just happens, if its the only device on the root hub, the hub
therefore resumes and the HCDs status_urb isn't yet available.
If a warm-reset request is detected, this sets the hubs event_bits,
which will prevent any auto-suspend and allows the hubs workqueue
to warm-reset the port later in port_event.

Signed-off-by: Jan-Marek Glogowski <>
Acked-by: Alan Stern <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Sasha Levin <>
drivers/usb/core/hub.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 8018f813972e0..d5fbd36cf4624 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -107,6 +107,8 @@ EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
static void hub_release(struct kref *kref);
static int usb_reset_and_verify_device(struct usb_device *udev);
static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
+static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
+ u16 portstatus);

static inline char *portspeed(struct usb_hub *hub, int portstatus)
@@ -1111,6 +1113,11 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)

+ /* Make sure a warm-reset request is handled by port_event */
+ if (type == HUB_RESUME &&
+ hub_port_warm_reset_required(hub, port1, portstatus))
+ set_bit(port1, hub->event_bits);
* Add debounce if USB3 link is in polling/link training state.
* Link will automatically transition to Enabled state after
 \ /
  Last update: 2019-10-19 00:22    [W:0.186 / U:1.332 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site