• Frank Li's avatar
    usb: xhci-plat: fix crash when suspend if remote wake enable · 9df47846
    Frank Li authored
    Crashed at i.mx8qm platform when suspend if enable remote wakeup
    
    Internal error: synchronous external abort: 96000210 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 2 PID: 244 Comm: kworker/u12:6 Not tainted 5.15.5-dirty #12
    Hardware name: Freescale i.MX8QM MEK (DT)
    Workqueue: events_unbound async_run_entry_fn
    pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
    pc : xhci_disable_hub_port_wake.isra.62+0x60/0xf8
    lr : xhci_disable_hub_port_wake.isra.62+0x34/0xf8
    sp : ffff80001394bbf0
    x29: ffff80001394bbf0 x28: 0000000000000000 x27: ffff00081193b578
    x26: ffff00081193b570 x25: 0000000000000000 x24: 0000000000000000
    x23: ffff00081193a29c x22: 0000000000020001 x21: 0000000000000001
    x20: 0000000000000000 x19: ffff800014e90490 x18: 0000000000000000
    x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
    x14: 0000000000000000 x13: 0000000000000002 x12: 0000000000000000
    x11: 0000000000000000 x10: 0000000000000960 x9 : ffff80001394baa0
    x8 : ffff0008145d1780 x7 : ffff0008f95b8e80 x6 : 000000001853b453
    x5 : 0000000000000496 x4 : 0000000000000000 x3 : ffff00081193a29c
    x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffff000814591620
    Call trace:
     xhci_disable_hub_port_wake.isra.62+0x60/0xf8
     xhci_suspend+0x58/0x510
     xhci_plat_suspend+0x50/0x78
     platform_pm_suspend+0x2c/0x78
     dpm_run_callback.isra.25+0x50/0xe8
     __device_suspend+0x108/0x3c0
    
    The basic flow:
    	1. run time suspend call xhci_suspend, xhci parent devices gate the clock.
            2. echo mem >/sys/power/state, system _device_suspend call xhci_suspend
            3. xhci_suspend call xhci_disable_hub_port_wake, which access register,
    	   but clock already gated by run time suspend.
    
    This problem was hidden by power domain driver, which call run time resume before it.
    
    But the below commit remove it and make this issue happen.
    	commit c1df456d ("PM: domains: Don't runtime resume devices at genpd_prepare()")
    
    This patch call run time resume before suspend to make sure clock is on
    before access register.
    Reviewed-by: default avatarPeter Chen <peter.chen@kernel.org>
    Cc: stable <stable@vger.kernel.org>
    Signed-off-by: default avatarFrank Li <Frank.Li@nxp.com>
    Testeb-by: default avatarAbel Vesa <abel.vesa@nxp.com>
    Link: https://lore.kernel.org/r/20220110172738.31686-1-Frank.Li@nxp.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    9df47846
xhci-plat.c 12.4 KB