From: Mika Westerberg mika.westerberg@linux.intel.com
commit 23257cfc1cb7202fd0065e9f4a6a0aac1c04c4a9 upstream.
We cannot call PM runtime functions in tb_retimer_scan() because it will also be called when retimers are scanned from userspace (happens when there is no device connected on ChromeOS for instance) and at the same USB4 port runtime resume hook. This leads to hang because neither can proceed.
Fix this by runtime resuming USB4 ports in tb_scan_port() instead. This makes sure the ports are runtime PM active when retimers are added under it while avoiding the reported hang as well.
Reported-by: Utkarsh Patel utkarsh.h.patel@intel.com Fixes: 1e56c88adecc ("thunderbolt: Runtime resume USB4 port when retimers are scanned") Cc: stable@vger.kernel.org Acked-by: Yehezkel Bernat YehezkelShB@gmail.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/thunderbolt/retimer.c | 17 +++-------------- drivers/thunderbolt/tb.c | 20 +++++++++++++++----- 2 files changed, 18 insertions(+), 19 deletions(-)
--- a/drivers/thunderbolt/retimer.c +++ b/drivers/thunderbolt/retimer.c @@ -427,13 +427,6 @@ int tb_retimer_scan(struct tb_port *port { u32 status[TB_MAX_RETIMER_INDEX + 1] = {}; int ret, i, last_idx = 0; - struct usb4_port *usb4; - - usb4 = port->usb4; - if (!usb4) - return 0; - - pm_runtime_get_sync(&usb4->dev);
/* * Send broadcast RT to make sure retimer indices facing this @@ -441,7 +434,7 @@ int tb_retimer_scan(struct tb_port *port */ ret = usb4_port_enumerate_retimers(port); if (ret) - goto out; + return ret;
/* * Enable sideband channel for each retimer. We can do this @@ -471,11 +464,11 @@ int tb_retimer_scan(struct tb_port *port break; }
- ret = 0; if (!last_idx) - goto out; + return 0;
/* Add on-board retimers if they do not exist already */ + ret = 0; for (i = 1; i <= last_idx; i++) { struct tb_retimer *rt;
@@ -489,10 +482,6 @@ int tb_retimer_scan(struct tb_port *port } }
-out: - pm_runtime_mark_last_busy(&usb4->dev); - pm_runtime_put_autosuspend(&usb4->dev); - return ret; }
--- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -628,11 +628,15 @@ static void tb_scan_port(struct tb_port * Downstream switch is reachable through two ports. * Only scan on the primary port (link_nr == 0). */ + + if (port->usb4) + pm_runtime_get_sync(&port->usb4->dev); + if (tb_wait_for_port(port, false) <= 0) - return; + goto out_rpm_put; if (port->remote) { tb_port_dbg(port, "port already has a remote\n"); - return; + goto out_rpm_put; }
tb_retimer_scan(port, true); @@ -647,12 +651,12 @@ static void tb_scan_port(struct tb_port */ if (PTR_ERR(sw) == -EIO || PTR_ERR(sw) == -EADDRNOTAVAIL) tb_scan_xdomain(port); - return; + goto out_rpm_put; }
if (tb_switch_configure(sw)) { tb_switch_put(sw); - return; + goto out_rpm_put; }
/* @@ -681,7 +685,7 @@ static void tb_scan_port(struct tb_port
if (tb_switch_add(sw)) { tb_switch_put(sw); - return; + goto out_rpm_put; }
/* Link the switches using both links if available */ @@ -733,6 +737,12 @@ static void tb_scan_port(struct tb_port
tb_add_dp_resources(sw); tb_scan_switch(sw); + +out_rpm_put: + if (port->usb4) { + pm_runtime_mark_last_busy(&port->usb4->dev); + pm_runtime_put_autosuspend(&port->usb4->dev); + } }
static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)