2023-04-28 19:54:28

by Andreas Kemnade

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Subject: [PATCH v2] gpiolib: fix allocation of mixed dynamic/static GPIOs

If static allocation and dynamic allocation GPIOs are present,
dynamic allocation pollutes the numberspace for static allocation,
causing static allocation to fail.
Enfore dynamic allocation above GPIO_DYNAMIC_BASE.

Seen on a GTA04 when omap-gpio (static) and twl-gpio (dynamic)
raced:
[some successful registrations of omap_gpio instances]
[ 2.553833] twl4030_gpio twl4030-gpio: gpio (irq 145) chaining IRQs 161..178
[ 2.561401] gpiochip_find_base: found new base at 160
[ 2.564392] gpio gpiochip5: (twl4030): added GPIO chardev (254:5)
[ 2.564544] gpio gpiochip5: registered GPIOs 160 to 177 on twl4030
[...]
[ 2.692169] omap-gpmc 6e000000.gpmc: GPMC revision 5.0
[ 2.697357] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
[ 2.703643] gpiochip_find_base: found new base at 178
[ 2.704376] gpio gpiochip6: (omap-gpmc): added GPIO chardev (254:6)
[ 2.704589] gpio gpiochip6: registered GPIOs 178 to 181 on omap-gpmc
[...]
[ 2.840393] gpio gpiochip7: Static allocation of GPIO base is deprecated, use dynamic allocation.
[ 2.849365] gpio gpiochip7: (gpio-160-191): GPIO integer space overlap, cannot add chip
[ 2.857513] gpiochip_add_data_with_key: GPIOs 160..191 (gpio-160-191) failed to register, -16
[ 2.866149] omap_gpio 48310000.gpio: error -EBUSY: Could not register gpio chip

On that device it is fixed invasively by
commit 92bf78b33b0b4 ("gpio: omap: use dynamic allocation of base")
but lets also fix that for devices where there is still
a mixture of static and dynamic allocation.

Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
Signed-off-by: Andreas Kemnade <[email protected]>
---
Changes in V2:
handle also the case of overlapping static allocation
across DYNAMIC_BASE

drivers/gpio/gpiolib.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 19bd23044b017..4472214fcd43a 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -193,6 +193,8 @@ static int gpiochip_find_base(int ngpio)
break;
/* nope, check the space right after the chip */
base = gdev->base + gdev->ngpio;
+ if (base < GPIO_DYNAMIC_BASE)
+ base = GPIO_DYNAMIC_BASE;
}

if (gpio_is_valid(base)) {
--
2.39.2


2023-04-29 06:54:53

by Christophe Leroy

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Subject: Re: [PATCH v2] gpiolib: fix allocation of mixed dynamic/static GPIOs



Le 28/04/2023 à 21:45, Andreas Kemnade a écrit :
> If static allocation and dynamic allocation GPIOs are present,
> dynamic allocation pollutes the numberspace for static allocation,
> causing static allocation to fail.
> Enfore dynamic allocation above GPIO_DYNAMIC_BASE.
>
> Seen on a GTA04 when omap-gpio (static) and twl-gpio (dynamic)
> raced:
> [some successful registrations of omap_gpio instances]
> [ 2.553833] twl4030_gpio twl4030-gpio: gpio (irq 145) chaining IRQs 161..178
> [ 2.561401] gpiochip_find_base: found new base at 160
> [ 2.564392] gpio gpiochip5: (twl4030): added GPIO chardev (254:5)
> [ 2.564544] gpio gpiochip5: registered GPIOs 160 to 177 on twl4030
> [...]
> [ 2.692169] omap-gpmc 6e000000.gpmc: GPMC revision 5.0
> [ 2.697357] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
> [ 2.703643] gpiochip_find_base: found new base at 178
> [ 2.704376] gpio gpiochip6: (omap-gpmc): added GPIO chardev (254:6)
> [ 2.704589] gpio gpiochip6: registered GPIOs 178 to 181 on omap-gpmc
> [...]
> [ 2.840393] gpio gpiochip7: Static allocation of GPIO base is deprecated, use dynamic allocation.
> [ 2.849365] gpio gpiochip7: (gpio-160-191): GPIO integer space overlap, cannot add chip
> [ 2.857513] gpiochip_add_data_with_key: GPIOs 160..191 (gpio-160-191) failed to register, -16
> [ 2.866149] omap_gpio 48310000.gpio: error -EBUSY: Could not register gpio chip
>
> On that device it is fixed invasively by
> commit 92bf78b33b0b4 ("gpio: omap: use dynamic allocation of base")
> but lets also fix that for devices where there is still
> a mixture of static and dynamic allocation.
>
> Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
> Signed-off-by: Andreas Kemnade <[email protected]>

Reviewed-by: <[email protected]>

> ---
> Changes in V2:
> handle also the case of overlapping static allocation
> across DYNAMIC_BASE
>
> drivers/gpio/gpiolib.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 19bd23044b017..4472214fcd43a 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -193,6 +193,8 @@ static int gpiochip_find_base(int ngpio)
> break;
> /* nope, check the space right after the chip */
> base = gdev->base + gdev->ngpio;
> + if (base < GPIO_DYNAMIC_BASE)
> + base = GPIO_DYNAMIC_BASE;
> }
>
> if (gpio_is_valid(base)) {

2023-04-29 11:37:23

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2] gpiolib: fix allocation of mixed dynamic/static GPIOs

On Fri, Apr 28, 2023 at 10:45 PM Andreas Kemnade <[email protected]> wrote:
>
> If static allocation and dynamic allocation GPIOs are present,
> dynamic allocation pollutes the numberspace for static allocation,
> causing static allocation to fail.
> Enfore dynamic allocation above GPIO_DYNAMIC_BASE.

Enforce

> Seen on a GTA04 when omap-gpio (static) and twl-gpio (dynamic)
> raced:
> [some successful registrations of omap_gpio instances]
> [ 2.553833] twl4030_gpio twl4030-gpio: gpio (irq 145) chaining IRQs 161..178
> [ 2.561401] gpiochip_find_base: found new base at 160
> [ 2.564392] gpio gpiochip5: (twl4030): added GPIO chardev (254:5)
> [ 2.564544] gpio gpiochip5: registered GPIOs 160 to 177 on twl4030
> [...]
> [ 2.692169] omap-gpmc 6e000000.gpmc: GPMC revision 5.0
> [ 2.697357] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
> [ 2.703643] gpiochip_find_base: found new base at 178
> [ 2.704376] gpio gpiochip6: (omap-gpmc): added GPIO chardev (254:6)
> [ 2.704589] gpio gpiochip6: registered GPIOs 178 to 181 on omap-gpmc
> [...]
> [ 2.840393] gpio gpiochip7: Static allocation of GPIO base is deprecated, use dynamic allocation.
> [ 2.849365] gpio gpiochip7: (gpio-160-191): GPIO integer space overlap, cannot add chip
> [ 2.857513] gpiochip_add_data_with_key: GPIOs 160..191 (gpio-160-191) failed to register, -16
> [ 2.866149] omap_gpio 48310000.gpio: error -EBUSY: Could not register gpio chip
>
> On that device it is fixed invasively by
> commit 92bf78b33b0b4 ("gpio: omap: use dynamic allocation of base")
> but lets also fix that for devices where there is still

let's

> a mixture of static and dynamic allocation.

It might be that it can be optimized, but OK for now. Thanks for fixing it.

Reviewed-by: Andy Shevchenko <[email protected]>

> Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
> Signed-off-by: Andreas Kemnade <[email protected]>
> ---
> Changes in V2:
> handle also the case of overlapping static allocation
> across DYNAMIC_BASE
>
> drivers/gpio/gpiolib.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 19bd23044b017..4472214fcd43a 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -193,6 +193,8 @@ static int gpiochip_find_base(int ngpio)
> break;
> /* nope, check the space right after the chip */
> base = gdev->base + gdev->ngpio;
> + if (base < GPIO_DYNAMIC_BASE)
> + base = GPIO_DYNAMIC_BASE;
> }
>
> if (gpio_is_valid(base)) {
> --
> 2.39.2
>


--
With Best Regards,
Andy Shevchenko