| From 099bd73dc17ed77aa8c98323e043613b6e8f54fc Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Mon, 10 Apr 2017 11:21:38 +0200 |
| Subject: [PATCH] serial: omap: fix runtime-pm handling on unbind |
| |
| commit 099bd73dc17ed77aa8c98323e043613b6e8f54fc upstream. |
| |
| 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> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Acked-by: Tony Lindgren <tony@atomide.com> |
| Cc: stable <stable@vger.kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c |
| index a4734649a0f0..50f2c5a5e450 100644 |
| --- a/drivers/tty/serial/omap-serial.c |
| +++ b/drivers/tty/serial/omap-serial.c |
| @@ -1783,9 +1783,13 @@ static int serial_omap_remove(struct platform_device *dev) |
| { |
| struct uart_omap_port *up = platform_get_drvdata(dev); |
| |
| + pm_runtime_get_sync(up->dev); |
| + |
| + uart_remove_one_port(&serial_omap_reg, &up->port); |
| + |
| + pm_runtime_dont_use_autosuspend(up->dev); |
| pm_runtime_put_sync(up->dev); |
| pm_runtime_disable(up->dev); |
| - uart_remove_one_port(&serial_omap_reg, &up->port); |
| pm_qos_remove_request(&up->pm_qos_request); |
| device_init_wakeup(&dev->dev, false); |
| |
| -- |
| 2.12.0 |
| |