• Guenter Roeck's avatar
    usb: chipidea: host: Disable port power only if previously enabled · 4adee561
    Guenter Roeck authored
    BugLink: https://bugs.launchpad.net/bugs/1859865
    
    commit c1ffba30 upstream.
    
    On shutdown, ehci_power_off() is called unconditionally to power off
    each port, even if it was never called to power on the port.
    For chipidea, this results in a call to ehci_ci_portpower() with a request
    to power off ports even if the port was never powered on.
    This results in the following warning from the regulator code.
    
    WARNING: CPU: 0 PID: 182 at drivers/regulator/core.c:2596 _regulator_disable+0x1a8/0x210
    unbalanced disables for usb_otg2_vbus
    Modules linked in:
    CPU: 0 PID: 182 Comm: init Not tainted 5.4.6 #1
    Hardware name: Freescale i.MX7 Dual (Device Tree)
    [<c0313658>] (unwind_backtrace) from [<c030d698>] (show_stack+0x10/0x14)
    [<c030d698>] (show_stack) from [<c1133afc>] (dump_stack+0xe0/0x10c)
    [<c1133afc>] (dump_stack) from [<c0349098>] (__warn+0xf4/0x10c)
    [<c0349098>] (__warn) from [<c0349128>] (warn_slowpath_fmt+0x78/0xbc)
    [<c0349128>] (warn_slowpath_fmt) from [<c09f36ac>] (_regulator_disable+0x1a8/0x210)
    [<c09f36ac>] (_regulator_disable) from [<c09f374c>] (regulator_disable+0x38/0xe8)
    [<c09f374c>] (regulator_disable) from [<c0df7bac>] (ehci_ci_portpower+0x38/0xdc)
    [<c0df7bac>] (ehci_ci_portpower) from [<c0db4fa4>] (ehci_port_power+0x50/0xa4)
    [<c0db4fa4>] (ehci_port_power) from [<c0db5420>] (ehci_silence_controller+0x5c/0xc4)
    [<c0db5420>] (ehci_silence_controller) from [<c0db7644>] (ehci_stop+0x3c/0xcc)
    [<c0db7644>] (ehci_stop) from [<c0d5bdc4>] (usb_remove_hcd+0xe0/0x19c)
    [<c0d5bdc4>] (usb_remove_hcd) from [<c0df7638>] (host_stop+0x38/0xa8)
    [<c0df7638>] (host_stop) from [<c0df2f34>] (ci_hdrc_remove+0x44/0xe4)
    ...
    
    Keeping track of the power enable state avoids the warning and traceback.
    
    Fixes: c8679a2f ("usb: chipidea: host: add portpower override")
    Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
    Cc: Peter Chen <peter.chen@freescale.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Acked-by: default avatarPeter Chen <peter.chen@nxp.com>
    Link: https://lore.kernel.org/r/20191226155754.25451-1-linux@roeck-us.netSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: default avatarConnor Kuehl <connor.kuehl@canonical.com>
    Signed-off-by: default avatarKhalid Elmously <khalid.elmously@canonical.com>
    4adee561
host.c 6.23 KB