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> --- drivers/pinctrl/mediatek/pinctrl-mt7622.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/mediatek/pinctrl-mt7622.c b/drivers/pinctrl/mediatek/pinctrl-mt7622.c index ad6da11..e3f1ab2 100644 --- a/drivers/pinctrl/mediatek/pinctrl-mt7622.c +++ b/drivers/pinctrl/mediatek/pinctrl-mt7622.c @@ -1459,6 +1459,9 @@ static int mtk_gpio_to_irq(struct gpio_chip *chip, unsigned int offset) struct mtk_pinctrl *hw = gpiochip_get_data(chip); unsigned long eint_n; + if (!hw->eint) + return -ENOTSUPP; + eint_n = offset; return mtk_eint_find_irq(hw->eint, eint_n); @@ -1471,7 +1474,8 @@ static int mtk_gpio_set_config(struct gpio_chip *chip, unsigned int offset, unsigned long eint_n; u32 debounce; - if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE) + if (!hw->eint || + pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE) return -ENOTSUPP; debounce = pinconf_to_config_argument(config); -- 2.7.4