• Hans de Goede's avatar
    phy: ti: tusb1210: Resolve charger-det crash if charger psy is unregistered · bf6e4ee5
    Hans de Goede authored
    The power_supply frame-work is not really designed for there to be
    long living in kernel references to power_supply devices.
    
    Specifically unregistering a power_supply while some other code has
    a reference to it triggers a WARN in power_supply_unregister():
    
    	WARN_ON(atomic_dec_return(&psy->use_cnt));
    
    Folllowed by the power_supply still getting removed and the
    backing data freed anyway, leaving the tusb1210 charger-detect code
    with a dangling reference, resulting in a crash the next time
    tusb1210_get_online() is called.
    
    Fix this by only holding the reference in tusb1210_get_online()
    freeing it at the end of the function. Note this still leaves
    a theoretical race window, but it avoids the issue when manually
    rmmod-ing the charger chip driver during development.
    
    Fixes: 48969a56 ("phy: ti: tusb1210: Add charger detection")
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Link: https://lore.kernel.org/r/20240406140821.18624-1-hdegoede@redhat.comSigned-off-by: default avatarVinod Koul <vkoul@kernel.org>
    bf6e4ee5
phy-tusb1210.c 16.2 KB