Messages in this thread | | | Date | Mon, 10 Apr 2017 09:15:24 -0700 | From | Tony Lindgren <> | Subject | Re: [PATCH 1/2] serial: omap: fix runtime-pm handling on unbind |
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* Johan Hovold <johan@kernel.org> [170410 02:27]: > An unbalanced and misplaced synchronous put was used to suspend the > device on driver unbind, something which with a likewise misplaced > pm_runtime_disable leads to external aborts when an open port is being > removed. > > Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010 > ... > [<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60) > [<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138) > [<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190) > [<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c) > [<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20) > [<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260) > [<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60) > [<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c) > > Fix this up by resuming the device before deregistering the port and by > suspending and disabling runtime pm only after the port has been > removed. > > Also make sure to disable autosuspend before disabling runtime pm so > that the usage count is balanced and device actually suspended before > returning. > > Note that due to a negative autosuspend delay being set in probe, the > unbalanced put would actually suspend the device on first driver unbind, > while rebinding and again unbinding would result in a negative > power.usage_count. > > Fixes: 7e9c8e7dbf3b ("serial: omap: make sure to suspend device before remove") > Cc: Felipe Balbi <balbi@kernel.org> > Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> > Cc: Tony Lindgren <tony@atomide.com> > Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
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