linux-next 2017-08-08 keyboard failure on Nokia N900

[Grygorii Strashko]

On 08/08/2017 06:12 AM, Pavel Machek wrote:
> Hi!
> 
>>> I tried today's linux-next. It boots on n900 (up to X), but then my
>>> screen locks and I can't get back. Touchscreen worked, so my guess is
>>> keyboard does not...? Ssh connection over usb still works.
>>
>> Confirmed, its the keyboard.
>>
>> Additionally, battery monitoring fails, because neither
>>
>> /sys/class/power_supply/{n900-,rx51-}battery/voltage_now
>>
>> exists.
> 
> And dmesg is helpful in this case:
> 
> [    0.675201] input: twl4030_pwrbutton as
> /devices/platform/68000000.ocp/48070000.i2c/i2c-1/1-0048/48070000.i2c:twl at 48:pwrbutton/input/input1
> [    0.676635] input: TWL4030 Keypad as
> /devices/platform/68000000.ocp/48070000.i2c/i2c-1/1-0048/48070000.i2c:twl at 48:keypad/input/input2
> [    0.679138] twl4030_keypad 48070000.i2c:twl at 48:keypad: request_irq
> failed for irq no=156: -13
> [    0.679779] twl4030_keypad: probe of 48070000.i2c:twl at 48:keypad
> failed with error -13
> [    0.682769] twl4030_madc 48070000.i2c:twl at 48:madc: could not
> request irq
> [    0.684051] twl4030_madc: probe of 48070000.i2c:twl at 48:madc failed
> with error -13
> [    0.685852] input: twl4030:vibrator as
> /devices/platform/68000000.ocp/48070000.i2c/i2c-1/1-0048/48070000.i2c:twl at 48:audio/twl4030-vibra/input/input3
> [    0.768890] omap_i2c 48070000.i2c: bus 1 rev3.3 at 2200 kHz
> 

I've not precisely checked it, but smth is telling me that below 
patch  can cause this:

commit 78daaca78ee57dead0f4aa5ee399f0499e81cd9e
Author: Julia Lawall <Julia.Lawall at lip6.fr>
Date:   Thu May 4 22:10:50 2017 +0200

    mfd: twl4030-irq: Drop unnecessary static
    
    Drop static on a local variable, when the variable is initialized before
    any use, on every possible execution path through the function.

--- a/drivers/mfd/twl4030-irq.c
+++ b/drivers/mfd/twl4030-irq.c
@@ -685,7 +685,7 @@ int twl4030_sih_setup(struct device *dev, int module, int irq_base)
 
 int twl4030_init_irq(struct device *dev, int irq_num)
 {
-       static struct irq_chip  twl4030_irq_chip;
+       struct irq_chip twl4030_irq_chip;


but if we will look at code - it can be seen that this variable is passed by reference to
irq_set_chip_and_handler(). 
Ops. And what will happen when twl4030_init_irq() returns ;)

-- 
regards,
-grygorii