Re: [PATCH (Option 2)] of/i2c: fix module load order issue causedby of_i2c.c

From: Jean Delvare
Date: Wed Sep 29 2010 - 11:43:47 EST


On Fri, 24 Sep 2010 16:15:18 -0600, Grant Likely wrote:
> Commit 959e85f7, "i2c: add OF-style registration and binding" caused a
> module dependency loop where of_i2c.c calls functions in i2c-core, and
> i2c-core calls of_i2c_register_devices() in of_i2c. This means that
> when i2c support is built as a module when CONFIG_OF is set, then
> neither i2c_core nor of_i2c are able to be loaded.
>
> This patch fixes the problem by moving the of_i2c_register_devices()
> calls back into the device drivers. Device drivers already
> specifically request the core code to parse the device tree for
> devices anyway by setting the of_node pointer, so it isn't a big
> deal to also call the registration function. The drivers just become
> slightly more verbose.
>
> Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-cpm.c | 5 +++++
> drivers/i2c/busses/i2c-ibm_iic.c | 3 +++
> drivers/i2c/busses/i2c-mpc.c | 1 +
> drivers/i2c/i2c-core.c | 4 ----
> 4 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
> index f7bd261..f2de3be 100644
> --- a/drivers/i2c/busses/i2c-cpm.c
> +++ b/drivers/i2c/busses/i2c-cpm.c
> @@ -677,6 +677,11 @@ static int __devinit cpm_i2c_probe(struct platform_device *ofdev,
> dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
> cpm->adap.name);
>
> + /*
> + * register OF I2C devices
> + */
> + of_i2c_register_devices(&cpm->adap);
> +
> return 0;
> out_shut:
> cpm_i2c_shutdown(cpm);
> diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c
> index 43ca32f..89eedf4 100644
> --- a/drivers/i2c/busses/i2c-ibm_iic.c
> +++ b/drivers/i2c/busses/i2c-ibm_iic.c
> @@ -761,6 +761,9 @@ static int __devinit iic_probe(struct platform_device *ofdev,
> dev_info(&ofdev->dev, "using %s mode\n",
> dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)");
>
> + /* Now register all the child nodes */
> + of_i2c_register_devices(adap);
> +
> return 0;
>
> error_cleanup:
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index a1c419a..b74e6dc 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -632,6 +632,7 @@ static int __devinit fsl_i2c_probe(struct platform_device *op,
> dev_err(i2c->dev, "failed to add adapter\n");
> goto fail_add;
> }
> + of_i2c_register_devices(&i2c->adap);
>
> return result;
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 6649176..a9589f5 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -32,7 +32,6 @@
> #include <linux/init.h>
> #include <linux/idr.h>
> #include <linux/mutex.h>
> -#include <linux/of_i2c.h>
> #include <linux/of_device.h>
> #include <linux/completion.h>
> #include <linux/hardirq.h>
> @@ -876,9 +875,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
> if (adap->nr < __i2c_first_dynamic_bus_num)
> i2c_scan_static_board_info(adap);
>
> - /* Register devices from the device tree */
> - of_i2c_register_devices(adap);
> -
> /* Notify drivers */
> mutex_lock(&core_lock);
> bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
>

I've applied this variant, thanks.

--
Jean Delvare
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