On Fri, Jun 22, 2018 at 5:49 AM sean.wang@mediatek.com wrote:
From: Sean Wang sean.wang@mediatek.com
When we are explicitly using GPIO hogging mechanism in the pinctrl node, such as:
&pio { line_input { gpio-hog; gpios = <95 0>, <96 0>, <97 0>; input; }; };A kernel panic happens at dereferencing a NULL pointer: In this case, the drvdata is still not setup properly yet when it is being accessed.
A better solution for fixing up this issue should be we should obtain the private data from struct gpio_chip using a specific gpiochip_get_data instead of a generic dev_get_drvdata.
[ 0.249424] Unable to handle kernel NULL pointer dereference at virtual address 000000c8 [ 0.257818] Mem abort info: [ 0.260704] ESR = 0x96000005 [ 0.263869] Exception class = DABT (current EL), IL = 32 bits [ 0.270011] SET = 0, FnV = 0 [ 0.273167] EA = 0, S1PTW = 0 [ 0.276421] Data abort info: [ 0.279398] ISV = 0, ISS = 0x00000005 [ 0.283372] CM = 0, WnR = 0 [ 0.286440] [00000000000000c8] user address but active_mm is swapper [ 0.293027] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 0.298795] Modules linked in: [ 0.301958] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc1+ #389 [ 0.308716] Hardware name: MediaTek MT7622 RFB1 board (DT) [ 0.314396] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.319362] pc : mtk_hw_pin_field_get+0x28/0x118 [ 0.324140] lr : mtk_hw_set_value+0x30/0x104 [ 0.328557] sp : ffffff800801b6d0 [ 0.331983] x29: ffffff800801b6d0 x28: ffffff80086b7970 [ 0.337484] x27: 0000000000000000 x26: ffffff80087b8000 [ 0.342986] x25: 0000000000000000 x24: ffffffc00324c230 [ 0.348487] x23: 0000000000000003 x22: 0000000000000000 [ 0.353988] x21: ffffff80087b8000 x20: 0000000000000000 [ 0.359489] x19: 0000000000000054 x18: 00000000fffff7c0 [ 0.364990] x17: 0000000000006300 x16: 000000000000003f [ 0.370492] x15: 000000000000000e x14: ffffffffffffffff [ 0.375993] x13: 0000000000000000 x12: 0000000000000020 [ 0.381494] x11: 0000000000000006 x10: 0101010101010101 [ 0.386995] x9 : fffffffffffffffa x8 : 0000000000000007 [ 0.392496] x7 : ffffff80085d63f8 x6 : 0000000000000003 [ 0.397997] x5 : 0000000000000054 x4 : ffffffc0031eb800 [ 0.403499] x3 : ffffff800801b728 x2 : 0000000000000003 [ 0.409000] x1 : 0000000000000054 x0 : 0000000000000000 [ 0.414502] Process swapper/0 (pid: 1, stack limit = 0x000000002a913c1c) [ 0.421441] Call trace: [ 0.423968] mtk_hw_pin_field_get+0x28/0x118 [ 0.428387] mtk_hw_set_value+0x30/0x104 [ 0.432445] mtk_gpio_set+0x20/0x28 [ 0.436052] mtk_gpio_direction_output+0x18/0x30 [ 0.440833] gpiod_direction_output_raw_commit+0x7c/0xa0 [ 0.446333] gpiod_direction_output+0x104/0x114 [ 0.451022] gpiod_configure_flags+0xbc/0xfc [ 0.455441] gpiod_hog+0x8c/0x140 [ 0.458869] of_gpiochip_add+0x27c/0x2d4 [ 0.462928] gpiochip_add_data_with_key+0x338/0x5f0 [ 0.467976] mtk_pinctrl_probe+0x388/0x400 [ 0.472217] platform_drv_probe+0x58/0xa4 [ 0.476365] driver_probe_device+0x204/0x44c [ 0.480783] __device_attach_driver+0xac/0x108 [ 0.485384] bus_for_each_drv+0x7c/0xac [ 0.489352] __device_attach+0xa0/0x144 [ 0.493320] device_initial_probe+0x10/0x18 [ 0.497647] bus_probe_device+0x2c/0x8c [ 0.501616] device_add+0x2f8/0x540 [ 0.505226] of_device_add+0x3c/0x44 [ 0.508925] of_platform_device_create_pdata+0x80/0xb8 [ 0.514245] of_platform_bus_create+0x290/0x3e8 [ 0.518933] of_platform_populate+0x78/0x100 [ 0.523352] of_platform_default_populate+0x24/0x2c [ 0.528403] of_platform_default_populate_init+0x94/0xa4 [ 0.533903] do_one_initcall+0x98/0x130 [ 0.537874] kernel_init_freeable+0x13c/0x1d4 [ 0.542385] kernel_init+0x10/0xf8 [ 0.545903] ret_from_fork+0x10/0x18 [ 0.549603] Code: 900020a1 f9400800 911dcc21 1400001f (f9406401) [ 0.555916] ---[ end trace de8c34787fdad3b3 ]--- [ 0.560722] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 0.560722] [ 0.570188] SMP: stopping secondary CPUs [ 0.574253] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 0.574253]
Cc: stable@vger.kernel.org Fixes: d6ed93551320 ("pinctrl: mediatek: add pinctrl driver for MT7622 SoC") Signed-off-by: Sean Wang sean.wang@mediatek.com
Patch applied for fixes.
Yours, Linus Walleij