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| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2015-08-17 16:13:30 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2015-08-26 10:27:39 +0300 |
| commit | 109fdf1572be86aaf681e69b30dc5ada90ce6f35 (patch) | |
| tree | f5d9934d2b273dd08066b91c832bd5fddc3acf2c /security | |
| parent | 78e1c896932df5b8bcdff7bf5417d8e72a4d0d6b (diff) | |
| download | linux-109fdf1572be86aaf681e69b30dc5ada90ce6f35.tar.xz | |
pinctrl: cherryview: Use raw_spinlock for locking
When running -rt kernel and an interrupt happens on a GPIO line controlled by
Intel Cherryview/Braswell pinctrl driver we get:
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/0
Preemption disabled at:[<ffffffff81092e9f>] cpu_startup_entry+0x17f/0x480
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.5-rt5 #16
...
Call Trace:
<IRQ> [<ffffffff816283c6>] dump_stack+0x4a/0x61
[<ffffffff81077e17>] ___might_sleep+0xe7/0x170
[<ffffffff8162d6cf>] rt_spin_lock+0x1f/0x50
[<ffffffff812e52ed>] chv_gpio_irq_ack+0x3d/0xa0
[<ffffffff810a72f5>] handle_edge_irq+0x75/0x180
[<ffffffff810a3457>] generic_handle_irq+0x27/0x40
[<ffffffff812e57de>] chv_gpio_irq_handler+0x7e/0x110
[<ffffffff810050aa>] handle_irq+0xaa/0x190
...
This is because desc->lock is raw_spinlock and is held when chv_gpio_irq_ack()
is called by the genirq core. chv_gpio_irq_ack() in turn takes pctrl->lock
which in -rt is an rt-mutex causing might_sleep() rightfully to complain about
sleeping function called from invalid context.
In order to keep -rt happy but at the same time make sure that register
accesses get serialized, convert the driver to use raw_spinlock instead.
Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'security')
0 files changed, 0 insertions, 0 deletions