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

[Julia Lawall]

On Tue, 8 Aug 2017, Grygorii Strashko wrote:

>
>
> 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@48:pwrbutton/input/input1
> > [    0.676635] input: TWL4030 Keypad as
> > /devices/platform/68000000.ocp/48070000.i2c/i2c-1/1-0048/48070000.i2c:twl@48:keypad/input/input2
> > [    0.679138] twl4030_keypad 48070000.i2c:twl@48:keypad: request_irq
> > failed for irq no=156: -13
> > [    0.679779] twl4030_keypad: probe of 48070000.i2c:twl@48:keypad
> > failed with error -13
> > [    0.682769] twl4030_madc 48070000.i2c:twl@48:madc: could not
> > request irq
> > [    0.684051] twl4030_madc: probe of 48070000.i2c:twl@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@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@xxxxxxx>
> 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 ;)

The patch is not correct as was already noted when it was submitted:

https://lkml.org/lkml/2017/7/15/169
https://lkml.org/lkml/2017/7/15/171

Do you need a patch reverting this one?

julia