linux-kernel - Re: I2C OF IRQ parsing issue due to probe ordering

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Date:	Thu, 30 Oct 2014 08:58:28 -0300
From:	Ezequiel Garcia <ezequiel@...guardiasur.com.ar>
To:	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-gpio@...r.kernel.org
CC:	Wolfram Sang <wsa@...-dreams.de>,
	Thierry Reding <thierry.reding@...il.com>
Subject: Re: I2C OF IRQ parsing issue due to probe ordering

Hi Laurent,

On 10/25/2014 07:13 PM, Laurent Pinchart wrote:
> Hello,
> 
> I recently ran into an issue with the OF IRQ parsing code in the I2C core
> (of_i2c_register_devices in drivers/i2c/i2c-core.c).
> 
> My DT contains the following nodes.
> 
>         gpio1: gpio@...51000 {
>                 ...
>                 #interrupt-cells = <2>;
>                 interrupt-controller;
>                 clocks = <&mstp9_clks R8A7790_CLK_GPIO1>;
>         };
> 
>         iic2: i2c@...20000 {
>                 #address-cells = <1>;
>                 #size-cells = <0>;
>                 ...
>                 hdmi@39 {
>                         compatible = "adi,adv7511w";
>                         reg = <0x39>;
>                         interrupt-parent = <&gpio1>;
>                         interrupts = <15 IRQ_TYPE_EDGE_FALLING>;
>                         ...
>                 };
>         };
> 
>         mstp9_clks: mstp9_clks@...50994 {
>                 ...
>         };
> 
> The i2c@...20000 node is probed before the gpio@...51000 node. The
> of_i2c_register_devices() function tries to register all children, including
> hdmi@39. It tries to parse and map the I2C client IRQ by calling
> irq_of_parse_and_map(), which returns 0 as the interrupt controller isn't
> probed yet. The adv7511 driver later probes the hdmi@39 device and gets
> client->irq set to 0.
> 
> We can't control the probe order.

Maybe I'm missing something, but I think your i2c adapter is probed with
a subsys_initcall (as many other adapters). Otherwise, I can't see why
it would be probed before the the gpio controller.

I think this initcall is your problem. Have you tried just using
platform_driver's probe?

-- 
Ezequiel Garcia, VanguardiaSur
www.vanguardiasur.com.ar


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