On Thu, Dec 14, 2023 at 12:50:21PM +0530, Sanath S wrote: > > On 12/14/2023 12:37 PM, Mika Westerberg wrote: > > On Thu, Dec 14, 2023 at 12:08:34PM +0530, Sanath S wrote: > > > On 12/13/2023 5:22 PM, Mika Westerberg wrote: > > > > On Wed, Dec 13, 2023 at 04:04:57PM +0530, Sanath S wrote: > > > > > On 12/13/2023 11:53 AM, Mika Westerberg wrote: > > > > > > On Wed, Dec 13, 2023 at 08:18:06AM +0200, Mika Westerberg wrote: > > > > > > > On Wed, Dec 13, 2023 at 07:49:14AM +0200, Mika Westerberg wrote: > > > > > > > > On Wed, Dec 13, 2023 at 12:46:35AM +0530, Sanath S wrote: > > > > > > > > > Boot firmware might have created tunnels of its own. Since we cannot > > > > > > > > > be sure they are usable for us. Tear them down and reset the ports > > > > > > > > > to handle it as a new hotplug for USB3 routers. > > > > > > > > > > > > > > > > > > Suggested-by: Mario Limonciello <mario.limonciello@xxxxxxx> > > > > > > > > > Signed-off-by: Sanath S <Sanath.S@xxxxxxx> > > > > > > > > > --- > > > > > > > > > drivers/thunderbolt/tb.c | 11 +++++++++++ > > > > > > > > > 1 file changed, 11 insertions(+) > > > > > > > > > > > > > > > > > > diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c > > > > > > > > > index fd49f86e0353..febd0b6972e3 100644 > > > > > > > > > --- a/drivers/thunderbolt/tb.c > > > > > > > > > +++ b/drivers/thunderbolt/tb.c > > > > > > > > > @@ -2598,6 +2598,17 @@ static int tb_start(struct tb *tb) > > > > > > > > > tb_switch_tmu_enable(tb->root_switch); > > > > > > > > > /* Full scan to discover devices added before the driver was loaded. */ > > > > > > > > > tb_scan_switch(tb->root_switch); > > > > > > > > > + /* > > > > > > > > > + * Boot firmware might have created tunnels of its own. Since we cannot > > > > > > > > > + * be sure they are usable for us, Tear them down and reset the ports > > > > > > > > > + * to handle it as new hotplug for USB4 routers. > > > > > > > > > + */ > > > > > > > > > + if (tb_switch_is_usb4(tb->root_switch)) { > > > > > > > > > + tb_switch_discover_tunnels(tb->root_switch, > > > > > > > > > + &tcm->tunnel_list, false); > > > > > > > > Why this is needed? > > > > > > > > > > > > > > > > It should be enough, to do simply something like this: > > > > > > > > > > > > > > > > if (tb_switch_is_usb4(tb->root_switch)) > > > > > > > > tb_switch_reset(tb->root_switch); > > > > > If we don't tear down of tunnels before performing the DPR, the PCIe > > > > > enumeration is failing. > > > > > > > > > > PCIe link is not coming up after DPR. Below log is missing without > > > > > performing path > > > > > deactivation before performing DPR and hence PCIe enumeration is not > > > > > initiated. > > > > > > > > > > [ 746.630865] pcieport 0000:00:03.1: pciehp: Slot(0-1): Card present > > > > > [ 746.630885] pcieport 0000:00:03.1: pciehp: Slot(0-1): Link Up > > > > > > > > > > I think when we do a DPR, it internally does some handling with PCI Path > > > > > Enable bit(PE). > > > > > So, deactivation of PCIe path is necessary for DPR to work. > > > > Rigth, it should be enough to reset the protocol adapter config and path > > > > config spaces. I guess using discovery at this point is fine too but I > > > > would at least check how complex doing the minimal "reset" turns out. > > > > > > > > I mean in tb_switch_reset() for USB4 v1 routers it can go over all the > > > > adapters and perform "cleanup" or so. > > > I gave it a thought yesterday and we can do something like this: > > > > > > We are already doing tb_discovery(tb) in tb_start. This would > > > discover the path configuration done by Boot firmware. > > > > > > Now, we can place the tb_switch_reset() right below that api with > > > conditions suggested by you. > > > > > > And tb_switch_reset() would internally DPR for all down steam ports. > > > > > > It can look something like below: > > > > > > /* Find out tunnels created by the boot firmware */ > > > tb_discover_tunnels(tb); > > > /* > > > * Reset USB4 v1 host router to get rid of possible tunnels the > > > * boot firmware created. This makes sure all the tunnels are > > > * created by us and thus have known configuration. > > > * > > > * For USB4 v2 and beyond we do this in nhi_reset() using the > > > * host router reset interface. > > > */ > > > if (host_reset && usb4_switch_version(tb->root_switch) == 1) > > > tb_switch_reset(tb->root_switch); > > > > > > With this, we are making sure while we get a unplug event after doing a DPR, > > > We are clearing all the paths established by Boot firmware. This wouldn't be > > > possible > > > if we had not discovered the paths before we perform DPR. > > > > > > It would create inconsistency for a new hot plug if we have not cleared the > > > path configurations > > > of previous hot unplug events. > > Right. I would still check if doing protocol adapter "reset" + path > > config space clear in tb_switch_reset() is enough and how complex that > > ends up to be. I think that's all what is needed. > > > > If it turns out too complex, yes I guess something like this: > > > > /* Find out tunnels created by the boot firmware */ > > tb_discover_tunnels(tb); > > /* Add DP resources from the DP tunnels created by the boot firmware */ > > tb_discover_dp_resources(tb); > > > > if (host_reset && usb4_switch_version(tb->root_switch) == 1) { > > struct tb_tunnel *n, *tunnel; > > > > list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) > > tb_deactivate_and_free_tunnel(tunnel); > > > > tb_switch_reset(tb->root_switch); > > } > > > > With proper comments would work, no? > Yes, this works. Tested it too and works fine. Cool. > Probably we can move tb_deactivate_and_free_tunnel() inside > tb_switch_reset() to make it > look better. Unfortunately that's not possible because tb_switch_reset() lives in switch.s (and should live there) and tb_deactivate_and_free_tunnel() is part of tb.c (as should be). This is actually why I would like to try the "reset" protocol adapters + their path config spaces in tb_switch_reset() as then that would work with any router and does not need to have any knowledge about tunnels or tb.c internals.