Hi, On Friday 05 October 2018 12:23 PM, Ricardo Ribalda Delgado wrote: > Current code assumes that the direction is input if direction_input > function is set. > This might not be the case on GPIOs with programmable direction. > > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx> > Tested-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx> This patch causes oops on TI's AM335x-ICEv2 board on next-20181011: [ 0.563797] OMAP GPIO hardware version 0.1 [ 0.577589] Unable to handle kernel NULL pointer dereference at virtual address 000002b8 [ 0.586127] pgd = (ptrval) [ 0.588934] [000002b8] *pgd=00000000 [ 0.592732] Internal error: Oops: 5 [#1] SMP ARM [ 0.597499] Modules linked in: [ 0.600668] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7-next-20181011 #70 [ 0.608466] Hardware name: Generic AM33XX (Flattened Device Tree) [ 0.614770] PC is at gpiod_hog+0x30/0x154 [ 0.618913] LR is at of_gpiochip_add+0x2fc/0x4e4 [ 0.623671] pc : [<c055213c>] lr : [<c0553ff0>] psr: 60000013 [ 0.630130] sp : ce09bba0 ip : cdf08095 fp : 00000000 [ 0.635516] r10: c0bfcf24 r9 : 00000000 r8 : 00000007 [ 0.640902] r7 : cdf08088 r6 : 00000000 r5 : 00000000 r4 : ce191e40 [ 0.647630] r3 : 00000000 r2 : 00000000 r1 : cdf08088 r0 : ce191e40 [ 0.654361] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 0.661718] Control: 10c5387d Table: 80004019 DAC: 00000051 [ 0.667642] Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) [...] [ 0.973593] [<c055213c>] (gpiod_hog) from [<c0553ff0>] (of_gpiochip_add+0x2fc/0x4e4) [ 0.981588] [<c0553ff0>] (of_gpiochip_add) from [<c05528a0>] (gpiochip_add_data_with_key+ 0x5a0/0x990) [ 0.991102] [<c05528a0>] (gpiochip_add_data_with_key) from [<c0556d8c>] (omap_gpio_probe+ 0x37c/0x75c) [ 1.000613] [<c0556d8c>] (omap_gpio_probe) from [<c06049c0>] (platform_drv_probe+0x48/0x9 8) [ 1.009237] [<c06049c0>] (platform_drv_probe) from [<c0602a04>] (really_probe+0x220/0x2d4 ) [ 1.017764] [<c0602a04>] (really_probe) from [<c0602c18>] (driver_probe_device+0x5c/0x164 ) [ 1.026293] [<c0602c18>] (driver_probe_device) from [<c0600d44>] (bus_for_each_drv+0x54/0 xb8) [ 1.035090] [<c0600d44>] (bus_for_each_drv) from [<c060276c>] (__device_attach+0xcc/0x13c ) [ 1.043615] [<c060276c>] (__device_attach) from [<c0601b88>] (bus_probe_device+0x88/0x90) [ 1.052051] [<c0601b88>] (bus_probe_device) from [<c05fea18>] (device_add+0x3d8/0x608) [ 1.060223] [<c05fea18>] (device_add) from [<c07343b8>] (of_platform_device_create_pdata+ 0x8c/0xc0) [ 1.069552] [<c07343b8>] (of_platform_device_create_pdata) from [<c07345c4>] (of_platform _bus_create+0x190/0x228) [ 1.080134] [<c07345c4>] (of_platform_bus_create) from [<c0734610>] (of_platform_bus_crea te+0x1dc/0x228) [ 1.089909] [<c0734610>] (of_platform_bus_create) from [<c073478c>] (of_platform_populate +0x5c/0xac) [ 1.099333] [<c073478c>] (of_platform_populate) from [<c0d12614>] (pdata_quirks_init+0x6c /0x90) [ 1.108306] [<c0d12614>] (pdata_quirks_init) from [<c0d12144>] (omap_generic_init+0xc/0x1 8) [ 1.116933] [<c0d12144>] (omap_generic_init) from [<c0d03eb0>] (customize_machine+0x1c/0x 30) [ 1.125645] [<c0d03eb0>] (customize_machine) from [<c01030e4>] (do_one_initcall+0x80/0x31 0) [ 1.134265] [<c01030e4>] (do_one_initcall) from [<c0d01244>] (kernel_init_freeable+0x3c4/ 0x4ac) [ 1.143238] [<c0d01244>] (kernel_init_freeable) from [<c0900f28>] (kernel_init+0x8/0x114) [ 1.151673] [<c0900f28>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20) [ 1.159475] Exception stack(0xce09bfb0 to 0xce09bff8) [ 1.164686] bfa0: 00000000 00000000 00000000 00000000 [ 1.173119] bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 1.181551] bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 1.188378] Code: 0a000002 e3530000 01a09003 159392b4 (e59352b8) [ 1.194766] ---[ end trace d5c17cd400f50a22 ]--- [ 1.199606] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.199606] [ 1.209052] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000 00b [ 1.209052] ]--- [ 3.172292] random: fast init done Full log: https://pastebin.ubuntu.com/p/jG8nN6CTBP/ Reverting this patch from linux-next allows to boot to prompt. Regards Vignesh > --- > drivers/gpio/gpiolib.c | 27 +++++++++++++-------------- > 1 file changed, 13 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 907019b67a58..e016b22658ff 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1349,20 +1349,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, > > spin_unlock_irqrestore(&gpio_lock, flags); > > - for (i = 0; i < chip->ngpio; i++) { > - struct gpio_desc *desc = &gdev->descs[i]; > - > - desc->gdev = gdev; > - > - /* REVISIT: most hardware initializes GPIOs as inputs (often > - * with pullups enabled) so power usage is minimized. Linux > - * code should set the gpio direction first thing; but until > - * it does, and in case chip->get_direction is not set, we may > - * expose the wrong direction in sysfs. > - */ > - desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0; > - } > - > #ifdef CONFIG_PINCTRL > INIT_LIST_HEAD(&gdev->pin_ranges); > #endif > @@ -1391,6 +1377,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, > if (status) > goto err_remove_chip; > > + for (i = 0; i < chip->ngpio; i++) { > + struct gpio_desc *desc = &gdev->descs[i]; > + > + desc->gdev = gdev; > + > + if (chip->get_direction && gpiochip_line_is_valid(chip, i)) > + desc->flags = !chip->get_direction(chip, i) ? > + (1 << FLAG_IS_OUT) : 0; > + else > + desc->flags = !chip->direction_input ? > + (1 << FLAG_IS_OUT) : 0; > + } > + > acpi_gpiochip_add(chip); > > machine_gpiochip_add(chip); >
