While remove host(e.g. for USB role switch from host to device), if runtime pm is enabled by user, below oops are occurs at dwc3 and cdns3 platform. Keep the xhci-plat device being active during remove host fixes them.

oops1: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000240 Mem abort info: ESR = 0x96000004 xhci-hcd xhci-hcd.1.auto: // Halt the HC xhci-hcd xhci-hcd.1.auto: // Reset the HC xhci-hcd xhci-hcd.1.auto: Wait for controller to be ready for doorbell rings EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 xhci-hcd xhci-hcd.1.auto: // Disabling event ring interrupts CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000001b7b18000 xhci-hcd xhci-hcd.1.auto: cleaning up memory xhci-hcd xhci-hcd.1.auto: Freed event ring xhci-hcd xhci-hcd.1.auto: Freed command ring [0000000000000240] pgd=0000000000000000 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 #1219 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 x29: ffff800011ddbbc0 x28: 0000000000000000 x27: 0000000000000008 x26: ffff800011b28000 x25: ffff80001012b328 x24: ffff800011ddbd48 x23: 0000000000000000 x22: ffff80001076ed78 x21: ffff000177896000 x20: ffff0001714ebce4 x19: ffff000177896000 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000000 x15: ffff800011b288c8 x14: 0000000000000261 x13: 0000000000000001 x12: 0000000000000001 x11: 0000000000000000 x10: 00000000000009c0 x9 : ffff800011ddbd40 x8 : fefefefefefefeff x7 : 0000000000000000 x6 : 000000003ca92688 x5 : 00ffffffffffffff x4 : 001b6b0b00000000 x3 : ffff0001714ebc10 x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff000177896250 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 Mem abort info: ESR = 0x96000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000008b05e8000 [0000000000000138] pgd=0000000000000000, p4d=0000000000000000 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-gd6235ff42e2b #101 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 x29: ffff80001006b5b0 x28: 0000000000000002 x27: ffff00083b74fd48 x26: ffff00083a365580 x25: ffff800010141458 x24: 0000000000000000 x23: 0000000000000000 x22: ffff000837e58138 x21: 0000000000000004 x20: ffff000837e58000 x19: ffff000837e58250 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000001 x15: 0000000000000004 x14: ffffffffffffffff x13: 0000000000004ed8 x12: ffff8000123d1000 x11: ffff800012158000 x10: ffff8000123d1360 x9 : ffff800010c74b00 x8 : 0000000000000007 x7 : 00000000000012c2 x6 : ffff8000123d1000 x5 : 0000000000000001 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000138 x1 : 0000000000000000 x0 : 0000000000000138 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 ]---

Cc: Baolin Wang baolin.wang@linaro.org Cc: Mathias Nyman mathias.nyman@linux.intel.com 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 --- changes for v2: - Add pm_runtime_put_noidle() to balance pm_runtime_get_sync(). - Move pm_runtime_set_suspended() to be after pm_runtime_disable().

drivers/usb/host/xhci-plat.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 1d4f6f8..ea460b9 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -362,6 +362,7 @@ static int xhci_plat_remove(struct platform_device *dev) 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); @@ -375,8 +376,9 @@ static int xhci_plat_remove(struct platform_device *dev) 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; }