[PATCH 5.6 143/194] usb: host: xhci-plat: keep runtime active when removing host

Greg Kroah-Hartman
2020-05-18T18:10:23Z

From: Li Jun <jun.li@nxp.com>

commit 1449cb2c2253d37d998c3714aa9b95416d16d379 upstream.

While removing the host (e.g. for USB role switch from host to device),
if runtime pm is enabled by user, below oops occurs on dwc3 and cdns3
platforms.
Keeping the xhci-plat device active during host removal, and disabling
runtime pm before calling pm_runtime_set_suspended() fixes them.

oops1:
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000240
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.4.3-00107-g64d454a-dirty
Hardware name: FSL i.MX8MP EVK (DT)
Workqueue: pm pm_runtime_work
pstate: 60000005 (nZCv daif -PAN -UAO)
pc : xhci_suspend+0x34/0x698
lr : xhci_plat_runtime_suspend+0x2c/0x38
sp : ffff800011ddbbc0
Call trace:
xhci_suspend+0x34/0x698
xhci_plat_runtime_suspend+0x2c/0x38
pm_generic_runtime_suspend+0x28/0x40
__rpm_callback+0xd8/0x138
rpm_callback+0x24/0x98
rpm_suspend+0xe0/0x448
rpm_idle+0x124/0x140
pm_runtime_work+0xa0/0xf8
process_one_work+0x1dc/0x370
worker_thread+0x48/0x468
kthread+0xf0/0x120
ret_from_fork+0x10/0x1c

oops2:
usb 2-1: USB disconnect, device number 2
xhci-hcd xhci-hcd.1.auto: remove, state 4
usb usb2: USB disconnect, device number 1
xhci-hcd xhci-hcd.1.auto: USB bus 2 deregistered
xhci-hcd xhci-hcd.1.auto: remove, state 4
usb usb1: USB disconnect, device number 1
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000138
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 7 Comm: kworker/u8:0 Not tainted 5.6.0-rc4-next-20200304-03578
Hardware name: Freescale i.MX8QXP MEK (DT)
Workqueue: 1-0050 tcpm_state_machine_work
pstate: 20000005 (nzCv daif -PAN -UAO)
pc : xhci_free_dev+0x214/0x270
lr : xhci_plat_runtime_resume+0x78/0x88
sp : ffff80001006b5b0
Call trace:
xhci_free_dev+0x214/0x270
xhci_plat_runtime_resume+0x78/0x88
pm_generic_runtime_resume+0x30/0x48
__rpm_callback+0x90/0x148
rpm_callback+0x28/0x88
rpm_resume+0x568/0x758
rpm_resume+0x260/0x758
rpm_resume+0x260/0x758
__pm_runtime_resume+0x40/0x88
device_release_driver_internal+0xa0/0x1c8
device_release_driver+0x1c/0x28
bus_remove_device+0xd4/0x158
device_del+0x15c/0x3a0
usb_disable_device+0xb0/0x268
usb_disconnect+0xcc/0x300
usb_remove_hcd+0xf4/0x1dc
xhci_plat_remove+0x78/0xe0
platform_drv_remove+0x30/0x50
device_release_driver_internal+0xfc/0x1c8
device_release_driver+0x1c/0x28
bus_remove_device+0xd4/0x158
device_del+0x15c/0x3a0
platform_device_del.part.0+0x20/0x90
platform_device_unregister+0x28/0x40
cdns3_host_exit+0x20/0x40
cdns3_role_stop+0x60/0x90
cdns3_role_set+0x64/0xd8
usb_role_switch_set_role.part.0+0x3c/0x68
usb_role_switch_set_role+0x20/0x30
tcpm_mux_set+0x60/0xf8
tcpm_reset_port+0xa4/0xf0
tcpm_detach.part.0+0x28/0x50
tcpm_state_machine_work+0x12ac/0x2360
process_one_work+0x1c8/0x470
worker_thread+0x50/0x428
kthread+0xfc/0x128
ret_from_fork+0x10/0x18
Code: c8037c02 35ffffa3 17ffe7c3 f9800011 (c85f7c01)
---[ end trace 45b1a173d2679e44 ]---

[minor commit message cleanup -Mathias]
Cc: Baolin Wang <baolin.wang@linaro.org>
Cc: <stable@vger.kernel.org>
Fixes: b0c69b4bace3 ("usb: host: plat: Enable xHCI plat runtime PM")
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Tested-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200514110432.25564-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/host/xhci-plat.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -363,6 +363,7 @@ static int xhci_plat_remove(struct platf
struct clk *reg_clk = xhci->reg_clk;
struct usb_hcd *shared_hcd = xhci->shared_hcd;

+ pm_runtime_get_sync(&dev->dev);
xhci->xhc_state |= XHCI_STATE_REMOVING;

usb_remove_hcd(shared_hcd);
@@ -376,8 +377,9 @@ static int xhci_plat_remove(struct platf
clk_disable_unprepare(reg_clk);
usb_put_hcd(hcd);

- pm_runtime_set_suspended(&dev->dev);
pm_runtime_disable(&dev->dev);
+ pm_runtime_put_noidle(&dev->dev);
+ pm_runtime_set_suspended(&dev->dev);

return 0;
}