Re: [PATCH v4 01/29] Revert "treewide: Fix probing of devices in DT overlays"

[Matti Vaittinen <mazziesaccount@gmail.com>]

On 24/11/2025 19:01, Rob Herring wrote:
> On Mon, Nov 24, 2025 at 10:44 AM Kalle Niemi <kaleposti@gmail.com> wrote:
>>
>>
>> On 11/24/25 16:53, Rob Herring wrote:
>>> On Mon, Nov 24, 2025 at 8:48 AM Kalle Niemi <kaleposti@gmail.com> wrote:
>>>> On 10/15/25 10:13, Herve Codina wrote:
>>>>> From: Saravana Kannan <saravanak@google.com>
>>>>>
>>>>> This reverts commit 1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924.
>>>>>
>>>>> While the commit fixed fw_devlink overlay handling for one case, it
>>>>> broke it for another case. So revert it and redo the fix in a separate
>>>>> patch.
>>>>>
>>>>> Fixes: 1a50d9403fb9 ("treewide: Fix probing of devices in DT overlays")
>>>>> Reported-by: Herve Codina <herve.codina@bootlin.com>
>>>>> Closes: https://lore.kernel.org/lkml/CAMuHMdXEnSD4rRJ-o90x4OprUacN_rJgyo8x6=9F9rZ+-KzjOg@mail.gmail.com/
>>>>> Closes: https://lore.kernel.org/all/20240221095137.616d2aaa@bootlin.com/
>>>>> Closes: https://lore.kernel.org/lkml/20240312151835.29ef62a0@bootlin.com/
>>>>> Signed-off-by: Saravana Kannan <saravanak@google.com>
>>>>> Link: https://lore.kernel.org/lkml/20240411235623.1260061-2-saravanak@google.com/
>>>>> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
>>>>> Acked-by: Mark Brown <broonie@kernel.org>
>>>>> ---
>>>>>     drivers/bus/imx-weim.c    | 6 ------
>>>>>     drivers/i2c/i2c-core-of.c | 5 -----
>>>>>     drivers/of/dynamic.c      | 1 -
>>>>>     drivers/of/platform.c     | 5 -----
>>>>>     drivers/spi/spi.c         | 5 -----
>>>>>     5 files changed, 22 deletions(-)
>>>>>
>>>>> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
>>>>> index 83d623d97f5f..87070155b057 100644
>>>>> --- a/drivers/bus/imx-weim.c
>>>>> +++ b/drivers/bus/imx-weim.c
>>>>> @@ -327,12 +327,6 @@ static int of_weim_notify(struct notifier_block *nb, unsigned long action,
>>>>>                                  "Failed to setup timing for '%pOF'\n", rd->dn);
>>>>>
>>>>>                 if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
>>>>> -                     /*
>>>>> -                      * Clear the flag before adding the device so that
>>>>> -                      * fw_devlink doesn't skip adding consumers to this
>>>>> -                      * device.
>>>>> -                      */
>>>>> -                     rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
>>>>>                         if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
>>>>>                                 dev_err(&pdev->dev,
>>>>>                                         "Failed to create child device '%pOF'\n",
>>>>> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
>>>>> index eb7fb202355f..30b48a428c0b 100644
>>>>> --- a/drivers/i2c/i2c-core-of.c
>>>>> +++ b/drivers/i2c/i2c-core-of.c
>>>>> @@ -176,11 +176,6 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
>>>>>                         return NOTIFY_OK;
>>>>>                 }
>>>>>
>>>>> -             /*
>>>>> -              * Clear the flag before adding the device so that fw_devlink
>>>>> -              * doesn't skip adding consumers to this device.
>>>>> -              */
>>>>> -             rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
>>>>>                 client = of_i2c_register_device(adap, rd->dn);
>>>>>                 if (IS_ERR(client)) {
>>>>>                         dev_err(&adap->dev, "failed to create client for '%pOF'\n",
>>>>> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
>>>>> index 2eaaddcb0ec4..b5be7484fb36 100644
>>>>> --- a/drivers/of/dynamic.c
>>>>> +++ b/drivers/of/dynamic.c
>>>>> @@ -225,7 +225,6 @@ static void __of_attach_node(struct device_node *np)
>>>>>         np->sibling = np->parent->child;
>>>>>         np->parent->child = np;
>>>>>         of_node_clear_flag(np, OF_DETACHED);
>>>>> -     np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
>>>>>
>>>>>         raw_spin_unlock_irqrestore(&devtree_lock, flags);
>>>>>
>>>>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
>>>>> index f77cb19973a5..ef9445ba168b 100644
>>>>> --- a/drivers/of/platform.c
>>>>> +++ b/drivers/of/platform.c
>>>>> @@ -739,11 +739,6 @@ static int of_platform_notify(struct notifier_block *nb,
>>>>>                 if (of_node_check_flag(rd->dn, OF_POPULATED))
>>>>>                         return NOTIFY_OK;
>>>>>
>>>>> -             /*
>>>>> -              * Clear the flag before adding the device so that fw_devlink
>>>>> -              * doesn't skip adding consumers to this device.
>>>>> -              */
>>>>> -             rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
>>>>>                 /* pdev_parent may be NULL when no bus platform device */
>>>>>                 pdev_parent = of_find_device_by_node(parent);
>>>>>                 pdev = of_platform_device_create(rd->dn, NULL,
>>>>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
>>>>> index 2e0647a06890..b22944a207c9 100644
>>>>> --- a/drivers/spi/spi.c
>>>>> +++ b/drivers/spi/spi.c
>>>>> @@ -4791,11 +4791,6 @@ static int of_spi_notify(struct notifier_block *nb, unsigned long action,
>>>>>                         return NOTIFY_OK;
>>>>>                 }
>>>>>
>>>>> -             /*
>>>>> -              * Clear the flag before adding the device so that fw_devlink
>>>>> -              * doesn't skip adding consumers to this device.
>>>>> -              */
>>>>> -             rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
>>>>>                 spi = of_register_spi_device(ctlr, rd->dn);
>>>>>                 put_device(&ctlr->dev);
>>>>>
>>>> Sorry, some of you will receive this message now for second time. First
>>>> message was sent to older series of patches.
>>>> -
>>>>
>>>> Hello,
>>>>
>>>> Test system testing drivers for ROHM ICs bisected this commit to cause
>>>> BD71847 drivers probe to not be called.
>>> This driver (and overlay support) is in linux-next or something out of
>>> tree on top of linux-next?
>>>
>>> Rob
>>
>> Yes the driver is in mainline linux: /drivers/mfd/rohm-bd718x7.c
> 
> I don't see any support to apply overlays in that driver.

Ah. Sorry for the confusion peeps. I asked Kalle to report this without 
proper consideration. 100% my bad.

While the bd718x7 drive indeed is mainline (and tested), the actual 
'glue-code' doing the overlay is part of the downstream test 
infrastructure. So yes, this is not a bug in upstream kernel - this 
falls in the category of an upstream change causing downstream things to 
break. So, feel free to say: "Go fix your code" :)

Now that this is sorted, if someone is still interested in helping us to 
get our upstream drivers tested - the downstream piece is just taking 
the compiled device-tree overlay at runtime (via bin-attribute file), 
and applying it using the of_overlay_fdt_apply(). The approach is 
working for our testing purposes when the device is added to I2C/SPI 
node which is already enabled. However, in case where we have the I2C 
disabled, and enable it in the same overlay where we add the new device 
- then the new device does not get probed.

I would be really grateful if someone had a pointer for us.

Yours,
	-- Matti

-- 
---
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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