Re: [PATCH v2 5/7] thunderbolt: increase the lane adapter link-up timeout value

["Chunfeng Yun (云春峰)" <Chunfeng.Yun@mediatek.com>]

On 二, 2026-11-10 at 15:39 +0100, Mika Westerberg wrote:
> On Tue, Nov 10, 2026 at 07:48:53PM +0800, Chunfeng Yun wrote:
> > when plug into a USB3 device into USB4 hub's downstream facing port
> > to trigger usb4 driver wakeup, encounter the lane link up timeout
> 
> USB4
ACK
> 
> > issue, then cause usb3 hub disconnect:
> 
> USB3
> 
> Everywhere.
OK
> 
> > 
> > usb4_hi NVDA8100:00: 0:1: failed to reach state TB_PORT_UP.
> > Ignoring port...
> 
> What's usb4_hi?
Sorry, forget update logs, it is the log from the draft usb4 platform
driver to test functions which change the driver name as 'usb4_hi',
I will reproduce it and get new logs.

Thanks
> 
> > usb4_hi NVDA8100:00: 0:1: lost during suspend, disconnecting
> > usb4_hi NVDA8100:00: 0:4 <-> 1:20 (USB3): deactivating
> > usb4_hi NVDA8100:00: deactivating USB3 Down path from 0:4 to 1:20
> > usb4_hi NVDA8100:00: deactivating USB3 Up path from 1:20 to 0:4
> > ...
> > thunderbolt 0-1: device disconnected
> > usb 2-1: USB disconnect, device number 10
> > 
> > Completes link training at ~1.48s (with two retimer) and
> > transitions
> > to TB_PORT_UP after change the timeout to 2s;
> > 
> > In the USB4 spec, Phase 5 (Link Equalization) alone is allowed up
> > to
> > 1000 ms. When add tPhase2~4 (200 ms), and retimer transaction
> > delays
> > (tCmdResponse = 50 ms), the physical link is allowed by spec to
> > take
> > 1200 ms to 1500 ms+ to complete initialization.
> 
> Okay that makes sense.
> 
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> > v2: change timeout from 2.5s to 2s
> > ---
> >  drivers/thunderbolt/switch.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/thunderbolt/switch.c
> > b/drivers/thunderbolt/switch.c
> > index 7ff3da79da76..7daee83c7ed8 100644
> > --- a/drivers/thunderbolt/switch.c
> > +++ b/drivers/thunderbolt/switch.c
> > @@ -486,7 +486,7 @@ int tb_port_state(struct tb_port *port)
> >   * @port: Port to wait
> >   * @wait_if_unplugged: Wait also when port is unplugged
> >   *
> > - * Wait up to 1 second for a port to reach state TB_PORT_UP. If
> > + * Wait up to 2 seconds for a port to reach state TB_PORT_UP. If
> >   * wait_if_unplugged is set then we also wait if the port is in
> > state
> >   * TB_PORT_UNPLUGGED (it takes a while for the device to be
> > registered after
> >   * switch resume). Otherwise we only wait if a device is
> > registered but the link
> > @@ -500,7 +500,7 @@ int tb_port_state(struct tb_port *port)
> >   */
> >  int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
> >  {
> > -	int retries = 10;
> > +	int retries = 20;
> >  	int state;
> >  	if (!port->cap_phy) {
> >  		tb_port_WARN(port, "does not have PHY\n");
> > -- 
> > 2.45.2