Re: [PATCH] gpiolib: Fix of_node inconsistency
On Mon, Aug 6, 2018 at 11:54 AM Biju Das wrote:
> Some platforms are not setting of_node in the driver. On these platforms
> defining gpio-reserved-ranges on device tree leads to kernel crash.
>
> It is due to some parts of the gpio core relying on the driver to set up
> of_node,while other parts do themselves.This inconsistent behaviour leads
> to a crash.
>
> gpiochip_add_data_with_key() calls gpiochip_init_valid_mask() with of_node
> as NULL. of_gpiochip_add() fills "of_node" and calls
> of_gpiochip_init_valid_mask().
>
> The fix is to move the assignment to chip->of_node from of_gpiochip_add()
> to gpiochip_add_data_with_key().
>
> Signed-off-by: Biju Das
Reviewed-by: Geert Uytterhoeven
Tested-by: Geert Uytterhoeven
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: [PATCH] gpiolib: Fix of_node inconsistency
On Mon, Aug 6, 2018 at 11:53 AM Biju Das wrote: > Some platforms are not setting of_node in the driver. On these platforms > defining gpio-reserved-ranges on device tree leads to kernel crash. > > It is due to some parts of the gpio core relying on the driver to set up > of_node,while other parts do themselves.This inconsistent behaviour leads > to a crash. > > gpiochip_add_data_with_key() calls gpiochip_init_valid_mask() with of_node > as NULL. of_gpiochip_add() fills "of_node" and calls > of_gpiochip_init_valid_mask(). > > The fix is to move the assignment to chip->of_node from of_gpiochip_add() > to gpiochip_add_data_with_key(). > > Signed-off-by: Biju Das After reading through context this seems like the right fix so patch applied! In the long run I want to get rid of this extra of_node in the chip, but it kind of requires every driver in the kernel to pass in a valid parent device representing the OF node. And there are so many hairy corner cases where they don't. Yours, Linus Walleij
[PATCH] gpiolib: Fix of_node inconsistency
Some platforms are not setting of_node in the driver. On these platforms
defining gpio-reserved-ranges on device tree leads to kernel crash.
It is due to some parts of the gpio core relying on the driver to set up
of_node,while other parts do themselves.This inconsistent behaviour leads
to a crash.
gpiochip_add_data_with_key() calls gpiochip_init_valid_mask() with of_node
as NULL. of_gpiochip_add() fills "of_node" and calls
of_gpiochip_init_valid_mask().
The fix is to move the assignment to chip->of_node from of_gpiochip_add()
to gpiochip_add_data_with_key().
Signed-off-by: Biju Das
---
drivers/gpio/gpiolib-of.c | 3 ---
drivers/gpio/gpiolib.c| 2 ++
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 28d9680..91174bf 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -620,9 +620,6 @@ int of_gpiochip_add(struct gpio_chip *chip)
{
int status;
- if ((!chip->of_node) && (chip->parent))
- chip->of_node = chip->parent->of_node;
-
if (!chip->of_node)
return 0;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e11a3bb..20fe531 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1256,6 +1256,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip,
void *data,
/* If the gpiochip has an assigned OF node this takes precedence */
if (chip->of_node)
gdev->dev.of_node = chip->of_node;
+ else
+ chip->of_node = gdev->dev.of_node;
#endif
gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
--
2.7.4
