| Message ID | 20181201154151.14890-1-linus.walleij@linaro.org |
|---|---|
| Headers | show |
| Series | Regulator ena_gpiod fixups | expand |
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
Hi Marek, first, thanks a *lot* for testing this, it is is much, much appreciated! On Mon, Dec 3, 2018 at 3:35 PM Marek Szyprowski <m.szyprowski@samsung.com> wrote: > 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: OK let's fix this! > Artik5 evaluation board (arch/arm/boot/dts/exynos3250-artik5-eval.dtb): > s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 Question: this is supposed to fail, right? It is something like a probe deferral or nonexisting GPIO controller? I look in the upstream tree: arch/arm/boot/dts/exynos3250-artik5.dtsi where s2mps14 is defined: ldo12_reg: LDO12 { /* VDD72 ~ VDD73 */ regulator-name = "VLDO12_2.8V"; regulator-min-microvolt = <2800000>; regulator-max-microvolt = <2800000>; samsung,ext-control-gpios = <&gpk0 2 GPIO_ACTIVE_HIGH>; }; I didn't really change anything about this, so this missing GPIO descriptor looks worrysome. Anyways what happens is this: gpio[reg] = devm_gpiod_get_from_of_node(...) if (IS_ERR(gpio[reg])) (...) continue; So this IS_ERR descriptor is left around. So we should probably handle erronoeus or NULL descriptors in gpiod_unhinge(). If you add this on top, does it start working? diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c index 5864e758d7f2..e35751bf0ea8 100644 --- a/drivers/gpio/gpiolib-devres.c +++ b/drivers/gpio/gpiolib-devres.c @@ -332,6 +332,8 @@ EXPORT_SYMBOL(devm_gpiod_put); void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc) { + if (IS_ERR_OR_NULL(desc)) + return; WARN_ON(devres_destroy(dev, devm_gpiod_release, devm_gpiod_match, desc)); } Yours, Linus Walleij
Hi Linus, On 2018-12-04 10:31, Linus Walleij wrote: > Hi Marek, > > first, thanks a *lot* for testing this, it is is much, much appreciated! > > On Mon, Dec 3, 2018 at 3:35 PM Marek Szyprowski > <m.szyprowski@samsung.com> wrote: > >> 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: > OK let's fix this! > >> Artik5 evaluation board (arch/arm/boot/dts/exynos3250-artik5-eval.dtb): >> s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 > Question: this is supposed to fail, right? It is something > like a probe deferral or nonexisting GPIO controller? It looks that the issue has been introduced earlier, but I didn't notice it. gpiod_get_from_of_node() doesn't handle GPIOD_FLAGS_BIT_NONEXCLUSIVE flag, the rest is just a result of it. Here we have a case, where 2 regulators provided by s2mps11 driver have a common gpio enable line (by PMIC design), so s2mps11 calls devm_gpiod_get_from_of_node() 2 times for exactly the same gpio descriptor. Fixing gpiod_get_from_of_node() for GPIOD_FLAGS_BIT_NONEXCLUSIVE is trivial: diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index cd84315ad586..ace194665b19 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4192,6 +4192,8 @@ struct gpio_desc *gpiod_get_from_of_node(struct device_node *node, transitory = flags & OF_GPIO_TRANSITORY; ret = gpiod_request(desc, label); + if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) + return desc; if (ret) return ERR_PTR(ret); With the above fix I still however get 2 warnings from devres functions, but this is probably caused by adding the same entry 2 times to the list without proper refcounting... I will check that later. > I look in the upstream tree: > arch/arm/boot/dts/exynos3250-artik5.dtsi > where s2mps14 is defined: > > ldo12_reg: LDO12 { > /* VDD72 ~ VDD73 */ > regulator-name = "VLDO12_2.8V"; > regulator-min-microvolt = <2800000>; > regulator-max-microvolt = <2800000>; > samsung,ext-control-gpios = <&gpk0 2 GPIO_ACTIVE_HIGH>; > }; > > I didn't really change anything about this, so this missing > GPIO descriptor looks worrysome. > > Anyways what happens is this: > > gpio[reg] = devm_gpiod_get_from_of_node(...) > if (IS_ERR(gpio[reg])) > (...) > continue; > > So this IS_ERR descriptor is left around. So we should > probably handle erronoeus or NULL descriptors in > gpiod_unhinge(). > > If you add this on top, does it start working? > > diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c > index 5864e758d7f2..e35751bf0ea8 100644 > --- a/drivers/gpio/gpiolib-devres.c > +++ b/drivers/gpio/gpiolib-devres.c > @@ -332,6 +332,8 @@ EXPORT_SYMBOL(devm_gpiod_put); > > void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc) > { > + if (IS_ERR_OR_NULL(desc)) > + return; > WARN_ON(devres_destroy(dev, devm_gpiod_release, > devm_gpiod_match, desc)); > } > Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
On Tue, Dec 4, 2018 at 11:33 AM Marek Szyprowski <m.szyprowski@samsung.com> wrote: > >> Artik5 evaluation board (arch/arm/boot/dts/exynos3250-artik5-eval.dtb): > >> s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 > > Question: this is supposed to fail, right? It is something > > like a probe deferral or nonexisting GPIO controller? > > It looks that the issue has been introduced earlier, but I didn't notice it. Sorry :( > gpiod_get_from_of_node() doesn't handle GPIOD_FLAGS_BIT_NONEXCLUSIVE > flag, the rest is just a result of it. OK I see. > Here we have a case, where 2 regulators provided by s2mps11 driver have > a common gpio enable line (by PMIC design), so s2mps11 calls > devm_gpiod_get_from_of_node() 2 times for exactly the same gpio descriptor. > > Fixing gpiod_get_from_of_node() for GPIOD_FLAGS_BIT_NONEXCLUSIVE is trivial: I will add a patch like this to the series! > With the above fix I still however get 2 warnings from devres functions, > but this is probably caused by adding the same entry 2 times to the list > without proper refcounting... I will check that later. Ah I see this regulator driver really excercise all corner cases of these nonexclusive GPIO lines. (Which is good!) Indeed devres is not going to like adding the same thing twice. I just sent a fix for that, subject: "gpio: devres: Handle nonexclusive GPIOs" you could perhaps try it on top of this series? I intend to merge that separately as a fix for current, as it is a bug. Yours, Linus Walleij
Hi Linus, On 2018-12-04 13:44, Linus Walleij wrote: > On Tue, Dec 4, 2018 at 11:33 AM Marek Szyprowski > <m.szyprowski@samsung.com> wrote: > >>>> Artik5 evaluation board (arch/arm/boot/dts/exynos3250-artik5-eval.dtb): >>>> s2mps11-pmic s2mps14-regulator: Failed to get control GPIO for 11/LDO12 >>> Question: this is supposed to fail, right? It is something >>> like a probe deferral or nonexisting GPIO controller? >> It looks that the issue has been introduced earlier, but I didn't notice it. > Sorry :( > >> gpiod_get_from_of_node() doesn't handle GPIOD_FLAGS_BIT_NONEXCLUSIVE >> flag, the rest is just a result of it. > OK I see. > >> Here we have a case, where 2 regulators provided by s2mps11 driver have >> a common gpio enable line (by PMIC design), so s2mps11 calls >> devm_gpiod_get_from_of_node() 2 times for exactly the same gpio descriptor. >> >> Fixing gpiod_get_from_of_node() for GPIOD_FLAGS_BIT_NONEXCLUSIVE is trivial: > I will add a patch like this to the series! > >> With the above fix I still however get 2 warnings from devres functions, >> but this is probably caused by adding the same entry 2 times to the list >> without proper refcounting... I will check that later. > Ah I see this regulator driver really excercise all corner cases of > these nonexclusive GPIO lines. (Which is good!) > > Indeed devres is not going to like adding the same thing twice. > > I just sent a fix for that, subject: > "gpio: devres: Handle nonexclusive GPIOs" > you could perhaps try it on top of this > series? I intend to merge that separately as a fix for current, > as it is a bug. Those 2 warnings were worrying me and I finally found! devres_* functions require to pass a pointer to the pointer as match_data, so desc must be passed as &desc to devres_find() and devres_destroy() functions, otherwise they always return -ENOENT. I will comment respective lines in your patches then. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
On Wed, Dec 5, 2018 at 3:30 PM Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > I just sent a fix for that, subject: > > "gpio: devres: Handle nonexclusive GPIOs" > > you could perhaps try it on top of this > > series? I intend to merge that separately as a fix for current, > > as it is a bug. > > Those 2 warnings were worrying me and I finally found! devres_* > functions require to pass a pointer to the pointer as match_data, so > desc must be passed as &desc to devres_find() and devres_destroy() > functions, otherwise they always return -ENOENT. I will comment > respective lines in your patches then. Ah thanks so much Marek! I will follow up with a v4 patch set immediately once I have it nailed down. Devres is tricky, and I'm not the smartest... Yours, Linus Walleij