Hi Linus, On 2018-12-01 16:41, Linus Walleij wrote: > Here is a second iteration of these fixups after thinking > over Charles Keepax excellent comments on the first series > of fixes. > > To make sure GPIO descriptors are never left dangling > (as far as I can tell!) I use this stepwise approach: > > 1. Fix the regulator_register() in the core to guarantee > that after calling this with a valid GPIO descriptor > in ena_gpiod it will be gpiod_put() if there is any > problem. > > 2. Fix up simple descriptor consumers to just gpiod_get() > and let the core take over the descriptor. Only handle > the errorpath up to this point. > > 3. Export gpiod_get_from_of_node() and let max77686 > obtain a GPIO descriptor from the device tree without > any devres make-up in the DT parsing callback. > > 4. Invent devm_gpiod_unhinge() that will remove the devres > monitoring of a devm_* allocated GPIO descriptor > right before handling it over to the regulator core, > and use this in the otherwise hairy da9211, > s5m8767, tps65090 and s2mps11 drivers.
The idea is good imho, but it looks that there are some missing cases in the code. Here are some logs from the boards I have access to: Artik5 evaluation board (arch/arm/boot/dts/exynos3250-artik5-eval.dtb): s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at drivers/gpio/gpiolib-devres.c:336 s2mps11_pmic_probe+0x1c4/0x49c Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc5-next-20181203-00020-gf6d64d46ca8c #1156 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c01125fc>] (unwind_backtrace) from [<c010e140>] (show_stack+0x10/0x14) [<c010e140>] (show_stack) from [<c0a510bc>] (dump_stack+0x98/0xc4) [<c0a510bc>] (dump_stack) from [<c0127078>] (__warn+0x10c/0x124) [<c0127078>] (__warn) from [<c01271a4>] (warn_slowpath_null+0x40/0x48) [<c01271a4>] (warn_slowpath_null) from [<c04e5c94>] (s2mps11_pmic_probe+0x1c4/0x49c) [<c04e5c94>] (s2mps11_pmic_probe) from [<c0583e60>] (platform_drv_probe+0x48/0x9c) [<c0583e60>] (platform_drv_probe) from [<c0581858>] (really_probe+0x274/0x400) [<c0581858>] (really_probe) from [<c0581ba0>] (driver_probe_device+0x78/0x1b8) [<c0581ba0>] (driver_probe_device) from [<c0581e08>] (__driver_attach+0x128/0x144) [<c0581e08>] (__driver_attach) from [<c057f71c>] (bus_for_each_dev+0x68/0xb4) [<c057f71c>] (bus_for_each_dev) from [<c0580a1c>] (bus_add_driver+0x1a8/0x268) [<c0580a1c>] (bus_add_driver) from [<c0582e44>] (driver_register+0x78/0x10c) [<c0582e44>] (driver_register) from [<c0103154>] (do_one_initcall+0x8c/0x410) [<c0103154>] (do_one_initcall) from [<c0f0124c>] (kernel_init_freeable+0x3c8/0x4d0) [<c0f0124c>] (kernel_init_freeable) from [<c0a6afd4>] (kernel_init+0x8/0x10c) random: fast init done [<c0a6afd4>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xd8cc1fb0 to 0xd8cc1ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 irq event stamp: 98209 hardirqs last enabled at (98217): [<c0192e14>] console_unlock+0x4ac/0x698 hardirqs last disabled at (98256): [<c0192a34>] console_unlock+0xcc/0x698 softirqs last enabled at (98276): [<c0102618>] __do_softirq+0x4f0/0x5e0 softirqs last disabled at (98289): [<c012f2f4>] irq_exit+0x160/0x16c ---[ end trace fed5502b2c7cd57b ]--- Unable to handle kernel paging request at virtual address fffffff0 pgd = (ptrval) [fffffff0] *pgd=597ce841, *pte=00000000, *ppte=00000000 Internal error: Oops: 27 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.20.0-rc5-next-20181203-00020-gf6d64d46ca8c #1156 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) PC is at devm_gpiod_match+0x4/0x18 LR is at devres_remove+0x68/0xb8 ... Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 4000406a DAC: 00000051 Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) Stack: (0xd8cc1d58 to 0xd8cc2000) ... [<c04a6f1c>] (devm_gpiod_match) from [<c05854b8>] (devres_remove+0x68/0xb8) [<c05854b8>] (devres_remove) from [<c0585cdc>] (devres_destroy+0x8/0x24) [<c0585cdc>] (devres_destroy) from [<c04a74a4>] (devm_gpiod_unhinge+0x1c/0x38) [<c04a74a4>] (devm_gpiod_unhinge) from [<c04e5c94>] (s2mps11_pmic_probe+0x1c4/0x49c) [<c04e5c94>] (s2mps11_pmic_probe) from [<c0583e60>] (platform_drv_probe+0x48/0x9c) [<c0583e60>] (platform_drv_probe) from [<c0581858>] (really_probe+0x274/0x400) [<c0581858>] (really_probe) from [<c0581ba0>] (driver_probe_device+0x78/0x1b8) [<c0581ba0>] (driver_probe_device) from [<c0581e08>] (__driver_attach+0x128/0x144) [<c0581e08>] (__driver_attach) from [<c057f71c>] (bus_for_each_dev+0x68/0xb4) [<c057f71c>] (bus_for_each_dev) from [<c0580a1c>] (bus_add_driver+0x1a8/0x268) [<c0580a1c>] (bus_add_driver) from [<c0582e44>] (driver_register+0x78/0x10c) [<c0582e44>] (driver_register) from [<c0103154>] (do_one_initcall+0x8c/0x410) [<c0103154>] (do_one_initcall) from [<c0f0124c>] (kernel_init_freeable+0x3c8/0x4d0) [<c0f0124c>] (kernel_init_freeable) from [<c0a6afd4>] (kernel_init+0x8/0x10c) [<c0a6afd4>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xd8cc1fb0 to 0xd8cc1ff8) ... ---[ end trace fed5502b2c7cd57c ]--- Rinato (arch/arm/boot/dts/exynos3250-rinato.dtb): s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 random: fast init done ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/gpio/gpiolib-devres.c:336 s2mps11_pmic_probe+0x1c4/0x49c Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc5-next-20181203-00020-gf6d64d46ca8c #1156 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c01125fc>] (unwind_backtrace) from [<c010e140>] (show_stack+0x10/0x14) [<c010e140>] (show_stack) from [<c0a510bc>] (dump_stack+0x98/0xc4) [<c0a510bc>] (dump_stack) from [<c0127078>] (__warn+0x10c/0x124) [<c0127078>] (__warn) from [<c01271a4>] (warn_slowpath_null+0x40/0x48) [<c01271a4>] (warn_slowpath_null) from [<c04e5c94>] (s2mps11_pmic_probe+0x1c4/0x49c) [<c04e5c94>] (s2mps11_pmic_probe) from [<c0583e60>] (platform_drv_probe+0x48/0x9c) [<c0583e60>] (platform_drv_probe) from [<c0581858>] (really_probe+0x274/0x400) [<c0581858>] (really_probe) from [<c0581ba0>] (driver_probe_device+0x78/0x1b8) [<c0581ba0>] (driver_probe_device) from [<c0581e08>] (__driver_attach+0x128/0x144) [<c0581e08>] (__driver_attach) from [<c057f71c>] (bus_for_each_dev+0x68/0xb4) [<c057f71c>] (bus_for_each_dev) from [<c0580a1c>] (bus_add_driver+0x1a8/0x268) [<c0580a1c>] (bus_add_driver) from [<c0582e44>] (driver_register+0x78/0x10c) [<c0582e44>] (driver_register) from [<c0103154>] (do_one_initcall+0x8c/0x410) [<c0103154>] (do_one_initcall) from [<c0f0124c>] (kernel_init_freeable+0x3c8/0x4d0) [<c0f0124c>] (kernel_init_freeable) from [<c0a6afd4>] (kernel_init+0x8/0x10c) [<c0a6afd4>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xd94c1fb0 to 0xd94c1ff8) ... irq event stamp: 114729 hardirqs last enabled at (114747): [<c0192e14>] console_unlock+0x4ac/0x698 hardirqs last disabled at (114764): [<c0192a34>] console_unlock+0xcc/0x698 softirqs last enabled at (114762): [<c0102618>] __do_softirq+0x4f0/0x5e0 softirqs last disabled at (114781): [<c012f2f4>] irq_exit+0x160/0x16c ---[ end trace 5961f9fa5249019f ]--- Unable to handle kernel paging request at virtual address fffffff0 pgd = (ptrval) [fffffff0] *pgd=5fece841, *pte=00000000, *ppte=00000000 Internal error: Oops: 27 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.20.0-rc5-next-20181203-00020-gf6d64d46ca8c #1156 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) PC is at devm_gpiod_match+0x4/0x18 LR is at devres_remove+0x68/0xb8 ... Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 4000406a DAC: 00000051 Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) Stack: (0xd94c1d58 to 0xd94c2000) ... [<c04a6f1c>] (devm_gpiod_match) from [<c05854b8>] (devres_remove+0x68/0xb8) [<c05854b8>] (devres_remove) from [<c0585cdc>] (devres_destroy+0x8/0x24) [<c0585cdc>] (devres_destroy) from [<c04a74a4>] (devm_gpiod_unhinge+0x1c/0x38) [<c04a74a4>] (devm_gpiod_unhinge) from [<c04e5c94>] (s2mps11_pmic_probe+0x1c4/0x49c) [<c04e5c94>] (s2mps11_pmic_probe) from [<c0583e60>] (platform_drv_probe+0x48/0x9c) [<c0583e60>] (platform_drv_probe) from [<c0581858>] (really_probe+0x274/0x400) [<c0581858>] (really_probe) from [<c0581ba0>] (driver_probe_device+0x78/0x1b8) [<c0581ba0>] (driver_probe_device) from [<c0581e08>] (__driver_attach+0x128/0x144) [<c0581e08>] (__driver_attach) from [<c057f71c>] (bus_for_each_dev+0x68/0xb4) [<c057f71c>] (bus_for_each_dev) from [<c0580a1c>] (bus_add_driver+0x1a8/0x268) [<c0580a1c>] (bus_add_driver) from [<c0582e44>] (driver_register+0x78/0x10c) [<c0582e44>] (driver_register) from [<c0103154>] (do_one_initcall+0x8c/0x410) [<c0103154>] (do_one_initcall) from [<c0f0124c>] (kernel_init_freeable+0x3c8/0x4d0) [<c0f0124c>] (kernel_init_freeable) from [<c0a6afd4>] (kernel_init+0x8/0x10c) [<c0a6afd4>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xd94c1fb0 to 0xd94c1ff8) ... ---[ end trace 5961f9fa524901a0 ]--- Other boards with other variants of s2mps11 or other PMICs works fine. > > Linus Walleij (13): > regulator: core: Track dangling GPIO descriptors > regulator: fixed: Let core handle GPIO descriptor > regulator: lm363x: Let core handle GPIO descriptor > regulator: lp8788-ldo: Let core handle GPIO descriptor > regulator: max8952: Let core handle GPIO descriptor > regulator: max8973: Let core handle GPIO descriptor > gpio: Export gpiod_get_from_of_node() > regulator: max77686: Let core handle GPIO descriptor > gpio: Add devm_gpiod_unhinge() > regulator: da9211: Hand over GPIO to regulator core > regulator: s5m8767: Hand over GPIO to regulator core > regulator: tps65090: Hand over GPIO to regulator core > regulator: s2mps11: Hand over GPIO to regulator core > > Documentation/driver-model/devres.txt | 1 + > drivers/gpio/gpiolib-devres.c | 17 ++++++++ > drivers/gpio/gpiolib.h | 6 --- > drivers/regulator/core.c | 55 +++++++++++++++++++++----- > drivers/regulator/da9211-regulator.c | 6 +++ > drivers/regulator/fixed.c | 6 ++- > drivers/regulator/lm363x-regulator.c | 8 +++- > drivers/regulator/lp8788-ldo.c | 8 +++- > drivers/regulator/max77686-regulator.c | 14 ++++--- > drivers/regulator/max8952.c | 10 +++-- > drivers/regulator/max8973-regulator.c | 23 +++++++---- > drivers/regulator/s2mps11.c | 7 +++- > drivers/regulator/s5m8767.c | 9 ++++- > drivers/regulator/tps65090-regulator.c | 6 +++ > include/linux/gpio/consumer.h | 23 +++++++++++ > 15 files changed, 161 insertions(+), 38 deletions(-) > Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
