Hi All,
On 9/14/22 9:16 AM, Tom Rini wrote:
On Wed, Sep 14, 2022 at 08:59:52AM -0500, Nate Drude wrote:
Hi Simon,
On 9/14/22 7:49 AM, Simon Glass wrote:
Hi Nate,
On Mon, 12 Sept 2022 at 14:57, Nate Drude <nat...@variscite.com> wrote:
Hi Simon and Fabio,
On 9/12/22 3:16 PM, Simon Glass wrote:
Hi,
On Mon, 12 Sept 2022 at 12:48, Fabio Estevam <feste...@gmail.com> wrote:
Hi Nate and Simon,
On Mon, Sep 12, 2022 at 2:55 PM Nate Drude <nat...@variscite.com> wrote:
gpio_hog_probe_all is invoked by init_sequence_r in board_r.c.
If device_probe fails for any gpio-hog, boot hangs with the following error:
initcall sequence 00000000fffc8e18 failed at call 000000004023b320 (err=-121)
### ERROR ### Please RESET the board ###
gpio-hog-optional allows the boot sequence to continue if device_probe
fails for optional gpio-hog(s).
Signed-off-by: Nate Drude <nat...@variscite.com>
---
doc/device-tree-bindings/gpio/gpio.txt | 1 +
drivers/gpio/gpio-uclass.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/doc/device-tree-bindings/gpio/gpio.txt
b/doc/device-tree-bindings/gpio/gpio.txt
index 1481ed607d..02d296316b 100644
--- a/doc/device-tree-bindings/gpio/gpio.txt
+++ b/doc/device-tree-bindings/gpio/gpio.txt
@@ -189,6 +189,7 @@ gpio-controller's driver probe function.
Each GPIO hog definition is represented as a child node of the GPIO
controller.
Required properties:
- gpio-hog: A property specifying that this child node represents a GPIO
hog.
+- gpio-hog-optional: A property specifying to continue boot when device_probe
fails in gpio_hog_probe_all
gpio-hog-optional property does not exist in Linux.
If this property is introduced then U-Boot and Linux devicetrees will
not be in sync.
Can this be fixed differently?
Nate, can you send a patch to Linux with the binding update?
Regards,
Simon
Thanks for your responses and feedback.
I don't think gpio-hog-optional is relevant to Linux.
Sure, but Linux is (for better or worse) the main repo for the device
tree bindings.
I am not understanding the action. I think you're suggesting I update the
Linux device tree bindings so they stay aligned with U-Boot, adding a
property gpio-hog-optional after this line:
https://github.com/torvalds/linux/blob/v6.0-rc5/Documentation/devicetree/bindings/gpio/gpio.txt#L191
However, since it's not relevant to Linux, I think it will be confusing
since it will have no effect and won't be be used in any Linux code.
Can you please advise what description I should use for the
gpio-hog-optional property so that the Linux maintainers would accept such a
patch?
Yes, that would be one way to go about this, and there are other
non-Linux bindings in the Linux kernel tree, but this might be the first
property of an existing binding, so that might also be a bit challenging
to get accepted, or find out what the preferred solution is.
[snip]
Do you have any suggestions for a better approach? Does it make sense
for gpio_hog_probe_all to cause a fatal error when the gpio hog probe
fails (most devices, including the gpio-expander, will not cause a hang
if they fail to probe)?
I think your approach is fine as is.
An alternate approach is to modify the default behavior so that
gpio_hog_probe_all will not trigger a fatal error. Do you think this is
better?
This too would be acceptable.
Thanks for the discussion and feedback. I prefer to avoid changing the
bindings in Linux if possible.
Would it be acceptable if I rework gpio_hog_probe_all so that it prints
an error "Failed to probe device..." if any device_probe fails, but
always returns 0 to avoid a fatal error in board_init_r? I can submit a
v2 patch, but I want to screen any problems with the approach first.
Thanks,
Nate
