Hi everyone, I have a problem with gpio functions. My kernel version is 3.8.2 and my SoC is a imX27 on a "home-made" board. First, when I boot, I had only the "Starting kernel..." message. So I rebuild my kernel with CONFIG_DEBUG_KERNEL, CONFIG_DEBUG_LL and CONFIG_EARLY_PRINTK. I have also add the line "earlyprintk=console,UART0,115200" on the bootargs of my Barebox. With that, I can see more messages : [...] Unable to handle kernel NULL pointer dereference at virtual address 0000002c pgd = c0004000 [0000002c] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 Not tainted (3.8.2+ #4) PC is at __gpio_to_irq+0x1c/0x44 LR is at navocap_baseboard_init+0xd8/0x2c8 pc : [<c01fd194>] lr : [<c04fd468>] psr: 60000053 sp : c7835ef0 ip : 00000079 fp : c05a5628 r10: c04f817c r9 : 00000000 r8 : c05a562c r7 : c7834000 r6 : 00000004 r5 : c05158c4 r4 : c0578844 r3 : 000005ac r2 : c05b0410 r1 : c7834000 r0 : 00000000 Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 0005317f Table: a0004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc78341b8) Stack: (0xc7835ef0 to 0xc7836000) 5ee0: c05158c4 c04fd468 00000002 10009000 5f00: 10009fff 00000000 00000200 00000000 00000000 00000000 c05158c4 c04fd348 5f20: c0578844 c04f819c c04d23dc c00087f8 00000003 00000003 c04d1b2c c06bd6a0 5f40: 00000000 c0578844 c05158c4 00000004 0000008b c05a562c c0515898 c04f6378 5f60: c05a5620 c04f62a0 00000003 00000003 c04f6378 c00403e0 00000000 00000000 5f80: c03cfee0 00000000 00000000 00000000 00000000 00000000 00000000 c03cfeec 5fa0: 00000000 00000000 c03cfee0 c00093b0 00000000 00000000 00000000 00000000 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00100000 000a1000 [<c01fd194>] (__gpio_to_irq+0x1c/0x44) from [<c04fd468>] (navocap_baseboard_init+0xd8/0x2c8) [<c04fd468>] (navocap_baseboard_init+0xd8/0x2c8) from [<c04f819c>] (customize_machine+0x20/0x30) [<c04f819c>] (customize_machine+0x20/0x30) from [<c00087f8>] (do_one_initcall+0x2c/0x168) [<c00087f8>] (do_one_initcall+0x2c/0x168) from [<c04f62a0>] (kernel_init_freeable+0xf4/0x1cc) [<c04f62a0>] (kernel_init_freeable+0xf4/0x1cc) from [<c03cfeec>] (kernel_init+0xc/0x164) [<c03cfeec>] (kernel_init+0xc/0x164) from [<c00093b0>] (ret_from_fork+0x14/0x24) Code: e0433100 e1a0c000 e7920003 e24dd004 (e590302c) ---[ end trace 61bb09c25216d85b ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b The problem is in the function "gpio_to_irq" in my board init functions (navocap_baseboard_init). To know which lines the opps appears, I have followed this tutorial : https://wiki.ubuntu.com/Kernel/KernelDebuggingTricks Thanks to it, I can notice that the opps appears when I called the "gpio_to_irq" function in : ret = request_irq(gpio_to_irq(IMX_GPIO_NR(2,14)), detect_irq, IRQF_TRIGGER_FALLING, "imx-mmc-detect", data); I have checked in other boards how to use this function and it is configured in the same way. I did see where I have made a mistake. Maybe in my config file where I have missed a configuration option ? How to solve this opps problem ? It would be very great if someone could give me some helps / feedbacks on this problem. Thank you in advance ! Best regards, -- Mylène JOSSERAND Navocap