Re: [RFC PATCH 6/7] gpio: omap: move pm runtime in irq_chip.irq_bus_lock/sync_unlock

2015-09-24 Thread Grygorii Strashko 

On 09/24/2015 03:28 PM, Linus Walleij wrote:

On Tue, Aug 18, 2015 at 4:10 AM, Grygorii Strashko
 wrote:


The PM runtime API can't be used in atomic contex on -RT even if
it's configured as irqsafe. As result, below error report can
be seen when PM runtime API called from IRQ chip's callbacks
irq_startup/irq_shutdown/irq_set_type, because they are
protected by RAW spinlock:


Grygorri I have a massive backlog of mail but if patch 6&7 are
still applicable, can you rebase and send me these for the v4.3-rc2+
tree?



sure.

Thanks.

--
regards,
-grygorii
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Re: [RFC PATCH 6/7] gpio: omap: move pm runtime in irq_chip.irq_bus_lock/sync_unlock

2015-09-24 Thread Linus Walleij 
On Tue, Aug 18, 2015 at 4:10 AM, Grygorii Strashko
 wrote:

> The PM runtime API can't be used in atomic contex on -RT even if
> it's configured as irqsafe. As result, below error report can
> be seen when PM runtime API called from IRQ chip's callbacks
> irq_startup/irq_shutdown/irq_set_type, because they are
> protected by RAW spinlock:

Grygorri I have a massive backlog of mail but if patch 6&7 are
still applicable, can you rebase and send me these for the v4.3-rc2+
tree?

Yours,
Linus Walleij
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To unsubscribe from this list: send the line "unsubscribe linux-omap" in
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[RFC PATCH 6/7] gpio: omap: move pm runtime in irq_chip.irq_bus_lock/sync_unlock

2015-08-18 Thread Grygorii Strashko 
The PM runtime API can't be used in atomic contex on -RT even if
it's configured as irqsafe. As result, below error report can
be seen when PM runtime API called from IRQ chip's callbacks
irq_startup/irq_shutdown/irq_set_type, because they are
protected by RAW spinlock:

BUG: sleeping function called from invalid context at 
kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 128, pid: 96, name: insmod
3 locks held by insmod/96:
 #0:  (dev-mutex){..}, at: [c04752c8] __driver_attach+0x54/0xa0
 #1:  (dev-mutex){..}, at: [c04752d4] __driver_attach+0x60/0xa0
 #2:  (class){..}, at: [c00a408c] __irq_get_desc_lock+0x60/0xa4
irq event stamp: 1834
hardirqs last  enabled at (1833): [c06ab2a4] 
_raw_spin_unlock_irqrestore+0x88/0x90
hardirqs last disabled at (1834): [c06ab068] _raw_spin_lock_irqsave+0x2c/0x64
softirqs last  enabled at (0): [c003d220] copy_process.part.52+0x410/0x19d8
softirqs last disabled at (0): [  (null)]   (null)
Preemption disabled at:[  (null)]   (null)

CPU: 1 PID: 96 Comm: insmod Tainted: GW  O
4.1.3-rt3-00618-g57e2387-dirty #184
Hardware name: Generic DRA74X (Flattened Device Tree)
[c00190f4] (unwind_backtrace) from [c0014734] (show_stack+0x20/0x24)
[c0014734] (show_stack) from [c06a62ec] (dump_stack+0x88/0xdc)
[c06a62ec] (dump_stack) from [c006ca44] (___might_sleep+0x198/0x2a8)
[c006ca44] (___might_sleep) from [c06ab6d4] (rt_spin_lock+0x30/0x70)
[c06ab6d4] (rt_spin_lock) from [c04815ac] (__pm_runtime_resume+0x68/0xa4)
[c04815ac] (__pm_runtime_resume) from [c04123f4] 
(omap_gpio_irq_type+0x188/0x1d8)
[c04123f4] (omap_gpio_irq_type) from [c00a64e4] 
(__irq_set_trigger+0x68/0x130)
[c00a64e4] (__irq_set_trigger) from [c00a7bc4] (irq_set_irq_type+0x44/0x6c)
[c00a7bc4] (irq_set_irq_type) from [c00abbf8] 
(irq_create_of_mapping+0x120/0x174)
[c00abbf8] (irq_create_of_mapping) from [c0577b74] (of_irq_get+0x48/0x58)
[c0577b74] (of_irq_get) from [c0540a14] (i2c_device_probe+0x54/0x15c)
[c0540a14] (i2c_device_probe) from [c04750dc] 
(driver_probe_device+0x184/0x2c8)
[c04750dc] (driver_probe_device) from [c0475310] (__driver_attach+0x9c/0xa0)
[c0475310] (__driver_attach) from [c0473238] (bus_for_each_dev+0x7c/0xb0)
[c0473238] (bus_for_each_dev) from [c0474af4] (driver_attach+0x28/0x30)
[c0474af4] (driver_attach) from [c0474760] (bus_add_driver+0x154/0x200)
[c0474760] (bus_add_driver) from [c0476348] (driver_register+0x88/0x108)
[c0476348] (driver_register) from [c0541600] (i2c_register_driver+0x3c/0x90)
[c0541600] (i2c_register_driver) from [bf003018] (pcf857x_init+0x18/0x24 
[gpio_pcf857x])
[bf003018] (pcf857x_init [gpio_pcf857x]) from [c000998c] 
(do_one_initcall+0x128/0x1e8)
[c000998c] (do_one_initcall) from [c06a4220] (do_init_module+0x6c/0x1bc)
[c06a4220] (do_init_module) from [c00dd0c8] (load_module+0x18e8/0x21c4)
[c00dd0c8] (load_module) from [c00ddaa0] (SyS_init_module+0xfc/0x158)
[c00ddaa0] (SyS_init_module) from [c000ff40] (ret_fast_syscall+0x0/0x54)

The IRQ chip interface defines only two callbacks which are executed in
non-atomic contex - irq_bus_lock/irq_bus_sync_unlock, so lets move
PM runtime calls there.

Cc: linux-rt-us...@vger.kernel.org
Signed-off-by: Grygorii Strashko grygorii.stras...@ti.com
---
 drivers/gpio/gpio-omap.c | 25 +++--
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 2ae0d47..c33595e 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -496,9 +496,6 @@ static int omap_gpio_irq_type(struct irq_data *d, unsigned 
type)
(type  (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
return -EINVAL;
 
-   if (!BANK_USED(bank))
-   pm_runtime_get_sync(bank-dev);
-
raw_spin_lock_irqsave(bank-lock, flags);
retval = omap_set_gpio_triggering(bank, offset, type);
if (retval) {
@@ -521,8 +518,6 @@ static int omap_gpio_irq_type(struct irq_data *d, unsigned 
type)
return 0;
 
 error:
-   if (!BANK_USED(bank))
-   pm_runtime_put(bank-dev);
return retval;
 }
 
@@ -797,9 +792,6 @@ static unsigned int omap_gpio_irq_startup(struct irq_data 
*d)
unsigned long flags;
unsigned offset = d-hwirq;
 
-   if (!BANK_USED(bank))
-   pm_runtime_get_sync(bank-dev);
-
raw_spin_lock_irqsave(bank-lock, flags);
 
if (!LINE_USED(bank-mod_usage, offset))
@@ -815,8 +807,6 @@ static unsigned int omap_gpio_irq_startup(struct irq_data 
*d)
return 0;
 err:
raw_spin_unlock_irqrestore(bank-lock, flags);
-   if (!BANK_USED(bank))
-   pm_runtime_put(bank-dev);
return -EINVAL;
 }
 
@@ -835,6 +825,19 @@ static void omap_gpio_irq_shutdown(struct irq_data *d)
omap_clear_gpio_debounce(bank, offset);
omap_disable_gpio_module(bank, offset);
raw_spin_unlock_irqrestore(bank-lock, flags);
+}
+
+static void omap_gpio_irq_bus_lock(struct irq_data *data)
+{
+   struct