Hi, On Tue, Aug 03, 2021 at 12:23:44AM +0530, Sanjay R Mehta wrote: > > > On 8/2/2021 8:56 PM, Mika Westerberg wrote: > > [CAUTION: External Email] > > > > On Mon, Aug 02, 2021 at 07:58:19AM -0500, Sanjay R Mehta wrote: > >> From: Sanjay R Mehta <sanju.mehta@xxxxxxx> > >> > >> Adapter0 (Port0) is the control adapter on the AMD USB4 host router. > >> As per USB4 spec in "Section 1.8", Control Adapters do not > >> have an Adapter Configuration Space". > >> > >> The read requests on Adapter0 time's out and driver initialization fails. > >> > >> Hence Disabling the Adapter in case of read-request timeout and continuing > >> the driver init. > >> > >> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx> > >> Signed-off-by: Sanjay R Mehta <sanju.mehta@xxxxxxx> > >> --- > >> drivers/thunderbolt/switch.c | 3 ++- > >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c > >> index 83b1ef3..effbfe4 100644 > >> --- a/drivers/thunderbolt/switch.c > >> +++ b/drivers/thunderbolt/switch.c > >> @@ -2747,8 +2747,9 @@ int tb_switch_add(struct tb_switch *sw) > >> } > >> ret = tb_init_port(&sw->ports[i]); > >> if (ret) { > >> + sw->ports[i].disabled = true; > >> dev_err(&sw->dev, "failed to initialize port %d\n", i); > >> - return ret; > >> + continue; > > > > Instead of this, would it work if we start the loop at 1? In case of the > > control adapter (0) tb_port_init() does not do anything useful anyway > > and it actually would simplify that function too if we get rid of the > > special casing. > > > Hi Mika, > > If we start loop from 1, it will work for host router > but this will skip port (0) on device router which may be valid port. For device router adapter 0 is also contror adapter so I think we can just skip it here unconditionally.