Re: [PATCH] pinctrl: mt7622: fix a kernel panic when pio don't work as EINT controller

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Thu, Jun 14, 2018 at 10:55 AM,  <sean.wang@xxxxxxxxxxxx> wrote:

> From: Sean Wang <sean.wang@xxxxxxxxxxxx>
>
> The function, external interrupt controller, is made as an optional to
> mt7622 pinctrl. But if we don't want pio behaves as an external interrupt
> controller, it would lead to hw->eint not be created properly and then
> will cause 'kernel NULL pointer' issue when gpiochip try to call .to_irq
> or .set_config. To fix it, check hw->eint before accessing the member.
>
> [    1.339494] Unable to handle kernel NULL pointer dereference at virtual
>                address 00000010
> [    1.347857] Mem abort info:
> [    1.350742]   ESR = 0x96000005
> [    1.353905]   Exception class = DABT (current EL), IL = 32 bits
> [    1.360024]   SET = 0, FnV = 0
> [    1.363185]   EA = 0, S1PTW = 0
> [    1.366431] Data abort info:
> [    1.369405]   ISV = 0, ISS = 0x00000005
> [    1.373363]   CM = 0, WnR = 0
> [    1.376437] [0000000000000010] user address but active_mm is swapper
> [    1.383005] Internal error: Oops: 96000005 [#1] PREEMPT SMP
> [    1.388748] Modules linked in:
> [    1.391897] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc1+ #344
> [    1.398625] Hardware name: MediaTek MT7622 RFB1 board (DT)
> [    1.404279] pstate: 80000005 (Nzcv daif -PAN -UAO)
> [    1.409221] pc : mtk_eint_find_irq+0x8/0x24
> [    1.413532] lr : mtk_gpio_to_irq+0x20/0x28
> [    1.417749] sp : ffffff800801baf0
> [    1.421161] x29: ffffff800801baf0 x28: ffffff8008792f40
> [    1.426637] x27: ffffff800886b000 x26: ffffff8008615620
> [    1.432113] x25: ffffffc00e4dbdc8 x24: ffffff80087b8000
> [    1.437589] x23: ffffffc00325a000 x22: ffffffc00325a010
> [    1.443066] x21: ffffffc0033dec18 x20: 00000000ffffffea
> [    1.448542] x19: ffffffc00e4db800 x18: 0000000000000130
> [    1.454018] x17: 000000000000000e x16: 0000000000000007
> [    1.459494] x15: ffffff80085ee000 x14: 0000000000000001
> [    1.464970] x13: 0000000000000001 x12: 0000000000000010
> [    1.470446] x11: 0101010101010101 x10: 0000000000000880
> [    1.475922] x9 : ffffff800801b990 x8 : ffffffc0030688e0
> [    1.481399] x7 : ffffff80080c0660 x6 : ffffffc00e4dbbb0
> [    1.486875] x5 : 0000000000000000 x4 : 0000000000000000
> [    1.492351] x3 : ffffff80082a92f4 x2 : 00000000fffffffa
> [    1.497826] x1 : 0000000000000051 x0 : 0000000000000000
> [    1.503305] Process swapper/0 (pid: 1, stack limit = 0x0000000054e053bd)
> [    1.510210] Call trace:
> [    1.512727]  mtk_eint_find_irq+0x8/0x24
> [    1.516677]  mtk_gpio_to_irq+0x20/0x28
> [    1.520539]  gpiod_to_irq+0x48/0x60
> [    1.524135]  mmc_gpiod_request_cd_irq+0x3c/0xc4
> [    1.528804]  mmc_start_host+0x6c/0x8c
> [    1.532575]  mmc_add_host+0x58/0x7c
> [    1.536168]  msdc_drv_probe+0x4fc/0x67c
> [    1.540121]  platform_drv_probe+0x58/0xa4
> [    1.544251]  driver_probe_device+0x204/0x44c
> [    1.548649]  __driver_attach+0x84/0xf8
> [    1.552512]  bus_for_each_dev+0x68/0xa0
> [    1.556461]  driver_attach+0x20/0x28
> [    1.560142]  bus_add_driver+0xec/0x240
> [    1.564002]  driver_register+0x98/0xe4
> [    1.567863]  __platform_driver_register+0x48/0x50
> [    1.572711]  mt_msdc_driver_init+0x18/0x20
> [    1.576932]  do_one_initcall+0x98/0x130
> [    1.580886]  kernel_init_freeable+0x13c/0x1d4
> [    1.585375]  kernel_init+0x10/0xf8
> [    1.588879]  ret_from_fork+0x10/0x18
> [    1.592564] Code: a8c67bfd d65f03c0 a9bf7bfd 910003fd (f9400800)
> [    1.598849] ---[ end trace 4bbcb7bc30e98492 ]---
> [    1.603677] Kernel panic - not syncing: Attempted to kill init!
>                exitcode=0x0000000b
> [    1.603677]
>
> cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: e6dabd38d8e7 ("pinctrl: mediatek: add EINT support to MT7622 SoC")
> Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>

Patch applied for fixes.

Yours,
Linus Walleij
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