Am 08.04.2014 13:29, schrieb Shawn Guo: > The .config() calls clk_get_rate() which might sleep, so we need to set > pwm_chip can_sleep flag. Otherwise, we see the following warning when > using pwm driven heartbeat led. > > WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:856 > mutex_trylock+0x184/0x1a4() > DEBUG_LOCKS_WARN_ON(in_interrupt()) > Modules linked in: > CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.0-rc5 #18 > [<c0015420>] (unwind_backtrace) from [<c0012cb0>] (show_stack+0x10/0x14) > [<c0012cb0>] (show_stack) from [<c001daf8>] (warn_slowpath_common+0x6c/0x8c) > [<c001daf8>] (warn_slowpath_common) from [<c001dbac>] > (warn_slowpath_fmt+0x30/0x40) > [<c001dbac>] (warn_slowpath_fmt) from [<c045df74>] (mutex_trylock+0x184/0x1a4) > [<c045df74>] (mutex_trylock) from [<c0360950>] (clk_prepare_lock+0xc/0xec) > [<c0360950>] (clk_prepare_lock) from [<c0362020>] (clk_get_rate+0xc/0x68) > [<c0362020>] (clk_get_rate) from [<c028d07c>] (mxs_pwm_config+0x20/0x198) > [<c028d07c>] (mxs_pwm_config) from [<c028bde8>] (pwm_config+0x60/0x70) > [<c028bde8>] (pwm_config) from [<c034b61c>] (__led_pwm_set+0x1c/0x3c) > [<c034b61c>] (__led_pwm_set) from [<c034bc3c>] > (led_heartbeat_function+0x70/0x110) > [<c034bc3c>] (led_heartbeat_function) from [<c00292f0>] > (call_timer_fn+0x7c/0x164) > [<c00292f0>] (call_timer_fn) from [<c00295c8>] (run_timer_softirq+0x1f0/0x260) > [<c00295c8>] (run_timer_softirq) from [<c002255c>] (__do_softirq+0xc4/0x2f0) > [<c002255c>] (__do_softirq) from [<c0022890>] (irq_exit+0xa4/0x10c) > [<c0022890>] (irq_exit) from [<c0010240>] (handle_IRQ+0x34/0x84) > [<c0010240>] (handle_IRQ) from [<c0013524>] (__irq_svc+0x44/0x54) > [<c0013524>] (__irq_svc) from [<c00107f8>] (arch_cpu_idle+0x40/0x48) > [<c00107f8>] (arch_cpu_idle) from [<c005deb8>] (cpu_startup_entry+0x70/0x198) > [<c005deb8>] (cpu_startup_entry) from [<c060aac8>] (start_kernel+0x2a8/0x2f8) > > Reported-by: Stefan Wahren <[email protected]> > Signed-off-by: Shawn Guo <[email protected]>
Tested-by: Stefan Wahren <[email protected]> > --- > drivers/pwm/pwm-mxs.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c > index 9475bc7..4f1bb4e 100644 > --- a/drivers/pwm/pwm-mxs.c > +++ b/drivers/pwm/pwm-mxs.c > @@ -147,6 +147,7 @@ static int mxs_pwm_probe(struct platform_device *pdev) > mxs->chip.dev = &pdev->dev; > mxs->chip.ops = &mxs_pwm_ops; > mxs->chip.base = -1; > + mxs->chip.can_sleep = true; > ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); > if (ret < 0) { > dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
