Re: Dell WD19TB Thunderbolt Dock not working with kernel > 6.6.28-1

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi Rick,

On Mon, Nov 04, 2024 at 07:04:08PM +0100, Rick wrote:
> Hi Mika
> 
> On 04-11-2024 07:36, Mika Westerberg wrote:
> > Hi Rick,
> > 
> > On Fri, Nov 01, 2024 at 01:57:50PM +0100, Rick wrote:
> > > I compiled 6.12.0-rc5-00181-g6c52d4da1c74-dirty resulting in docking station
> > > not working.
> > > 
> > > Then I compiled 6.12.0-rc5-00181-g6c52d4da1c74-dirty without commit
> > > c6ca1ac9f472 (reverted), and now the docking station works correctly (as in
> > > screen output + USBs + Ethernet)
> > > 
> > > So it seems c6ca1ac9f472 is causing issues for my setup.
> > 
> > Okay, thanks for testing!
> > 
> > It indeed looks like there is no any kind of link issues anymore with
> > that one reverted. So my suspect is that we are taking too long before
> > we enumerate the device router which makes it to reset the link.
> > 
> > Can you try the below patch too on top of v6.12-rcX (without the revert)
> > and see if that still keeps it working? This one cuts down the delay to
> > 1ms which I'm hoping is sufficient for the device. Can you share
> > dmesg+trace from that test as well?
> > 
> > diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
> > index c6dcc23e8c16..1b740d7fc7da 100644
> > --- a/drivers/thunderbolt/usb4.c
> > +++ b/drivers/thunderbolt/usb4.c
> > @@ -48,7 +48,7 @@ enum usb4_ba_index {
> >   /* Delays in us used with usb4_port_wait_for_bit() */
> >   #define USB4_PORT_DELAY			50
> > -#define USB4_PORT_SB_DELAY		5000
> > +#define USB4_PORT_SB_DELAY		1000
> >   static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
> >   				 u32 *metadata, u8 *status,
> 
> See below pasts without the revert, and with the above provided patch.
> 
> dmesg with patch (and without the revert):
> https://gist.github.com/ricklahaye/8412af228063546dd8375ca796fffeef
> tbtrace with patch (and without the revert):
> https://gist.github.com/ricklahaye/4b9cbeeb36b546c6686ce79a044a2d61
> 
> Seems to be working correctly with the provided patch.
> Thank you!

Thanks for testing! Yes, logs look good now.

I will submit this fix upstream today then. Do you mind providing me your
full name and email so that I can add tag like

Reported-by: Rick ...

in the commit message?