Hi Guenter,
> On Jan 15, 2015, at 20:55 , Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On Thu, Jan 15, 2015 at 08:33:18PM +0200, Pantelis Antoniou wrote:
>> Mark (and unmark) device nodes with the POPULATE flag as appropriate.
>> This is required to avoid multi probing when using I2C and device
>> overlays containing a mux.
>> This patch is also more careful with the release of the adapter device
>> which caused a deadlock with muxes, and does not break the build
>> on !OF since the node flag accessors are not defined then.
>>
>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>> ---
>> drivers/i2c/i2c-core.c | 18 +++++++++++++++++-
>> 1 file changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
>> index 39d25a8..1d44e3a 100644
>> --- a/drivers/i2c/i2c-core.c
>> +++ b/drivers/i2c/i2c-core.c
>> @@ -1122,6 +1122,10 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
>> */
>> void i2c_unregister_device(struct i2c_client *client)
>> {
>> +#if IS_ENABLED(CONFIG_OF_DYNAMIC)
>
> Hi Pantelis,
>
> I thought I read a note somewhere a couple of days ago suggesting that
> CONFIG_OF_DYNAMIC would go away soon. Also, of_node_clear_flag is defined
> in #ifdef CONFIG_OF, and AFAICS none of the other callers set OF_POPULATED
> in the context of CONFIG_OF_DYNAMIC. Given that, wouldn't it be better
> to use CONFIG_OF ?
>
> Thanks,
> Guenter
>
Well, I thought about it. Thing is that the notifier is under CONFIG_DYNAMIC,
and it seems it’s natural to be that way.
When we move to always enabling CONFIG_DYNAMIC the change to CONFIG_OF will be
part of the conversion.
Regards
— Pantelis
>> + if (client->dev.of_node)
>> + of_node_clear_flag(client->dev.of_node, OF_POPULATED);
>> +#endif
>> device_unregister(&client->dev);
>> }
>> EXPORT_SYMBOL_GPL(i2c_unregister_device);
>> @@ -1441,8 +1445,11 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
>>
>> dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
>>
>> - for_each_available_child_of_node(adap->dev.of_node, node)
>> + for_each_available_child_of_node(adap->dev.of_node, node) {
>> + if (of_node_test_and_set_flag(node, OF_POPULATED))
>> + continue;
>> of_i2c_register_device(adap, node);
>> + }
>> }
>>
>> static int of_dev_node_match(struct device *dev, void *data)
>> @@ -1976,6 +1983,11 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
>> if (adap == NULL)
>> return NOTIFY_OK; /* not for us */
>>
>> + if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
>> + put_device(&adap->dev);
>> + return NOTIFY_OK;
>> + }
>> +
>> client = of_i2c_register_device(adap, rd->dn);
>> put_device(&adap->dev);
>>
>> @@ -1986,6 +1998,10 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
>> }
>> break;
>> case OF_RECONFIG_CHANGE_REMOVE:
>> + /* already depopulated? */
>> + if (!of_node_check_flag(rd->dn, OF_POPULATED))
>> + return NOTIFY_OK;
>> +
>> /* find our device by node */
>> client = of_find_i2c_device_by_node(rd->dn);
>> if (client == NULL)
>> --
>> 1.7.12
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