Re: [PATCH 3/4] thunderbolt: Fix adapter init handling during switch add

Mika Westerberg
2021-08-02T15:26:18Z

On Mon, Aug 02, 2021 at 07:58:19AM -0500, Sanjay R Mehta wrote:
> From: Sanjay R Mehta <sanju.mehta@amd.com>
>
> 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@amd.com>
> Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
> ---
> 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.

> }
> }
>
> --
> 2.7.4