diff mbox

[v2,2/2] i2c: mark device nodes only in case of successful instantiation

Message ID 20161017135957.20297-3-ralf@ramses-pyramidenbau.de (mailing list archive)
State New, archived
Headers show

Commit Message

Ralf Ramsauer Oct. 17, 2016, 1:59 p.m. UTC
Instantiated I2C device nodes are marked with OF_POPULATE. This was
introduced in 4f001fd. On unloading, loaded device nodes will of course
be unmarked. The problem are nodes that fail during initialisation: If a
node fails, it won't be unloaded and hence not be unmarked.

If a I2C driver module is unloaded and reloaded, it will skip nodes that
failed before.

Skip device nodes that are already populated and mark them only in case
of success.

Note that the same issue exists for SPI.

Fixes: 4f001fd ("i2c: Mark instantiated device nodes with OF_POPULATE")
Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>
---
 drivers/i2c/i2c-core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Geert Uytterhoeven Oct. 17, 2016, 2:16 p.m. UTC | #1
On Mon, Oct 17, 2016 at 3:59 PM, Ralf Ramsauer
<ralf@ramses-pyramidenbau.de> wrote:
> Instantiated I2C device nodes are marked with OF_POPULATE. This was
> introduced in 4f001fd. On unloading, loaded device nodes will of course
> be unmarked. The problem are nodes that fail during initialisation: If a
> node fails, it won't be unloaded and hence not be unmarked.
>
> If a I2C driver module is unloaded and reloaded, it will skip nodes that
> failed before.
>
> Skip device nodes that are already populated and mark them only in case
> of success.
>
> Note that the same issue exists for SPI.
>
> Fixes: 4f001fd ("i2c: Mark instantiated device nodes with OF_POPULATE")
> Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c

> @@ -1695,7 +1696,14 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
>         for_each_available_child_of_node(bus, node) {
>                 if (of_node_test_and_set_flag(node, OF_POPULATED))
>                         continue;
> -               of_i2c_register_device(adap, node);
> +
> +               client = of_i2c_register_device(adap, node);
> +               if (IS_ERR(client)) {
> +                       dev_warn(&adap->dev,
> +                                "Failed to create I2C device for %s\n",
> +                                node->full_name);

I don't think there's a need to add this warning, as of_i2c_register_device()
already prints messages in all failure paths.

> +                       of_node_clear_flag(node, OF_POPULATED);
> +               }
>         }

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Ralf Ramsauer Oct. 17, 2016, 2:37 p.m. UTC | #2
On 10/17/2016 04:16 PM, Geert Uytterhoeven wrote:
> On Mon, Oct 17, 2016 at 3:59 PM, Ralf Ramsauer
> <ralf@ramses-pyramidenbau.de> wrote:
>> Instantiated I2C device nodes are marked with OF_POPULATE. This was
>> introduced in 4f001fd. On unloading, loaded device nodes will of course
>> be unmarked. The problem are nodes that fail during initialisation: If a
>> node fails, it won't be unloaded and hence not be unmarked.
>>
>> If a I2C driver module is unloaded and reloaded, it will skip nodes that
>> failed before.
>>
>> Skip device nodes that are already populated and mark them only in case
>> of success.
>>
>> Note that the same issue exists for SPI.
>>
>> Fixes: 4f001fd ("i2c: Mark instantiated device nodes with OF_POPULATE")
>> Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>
> 
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
>> --- a/drivers/i2c/i2c-core.c
>> +++ b/drivers/i2c/i2c-core.c
> 
>> @@ -1695,7 +1696,14 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
>>         for_each_available_child_of_node(bus, node) {
>>                 if (of_node_test_and_set_flag(node, OF_POPULATED))
>>                         continue;
>> -               of_i2c_register_device(adap, node);
>> +
>> +               client = of_i2c_register_device(adap, node);
>> +               if (IS_ERR(client)) {
>> +                       dev_warn(&adap->dev,
>> +                                "Failed to create I2C device for %s\n",
>> +                                node->full_name);
> 
> I don't think there's a need to add this warning, as of_i2c_register_device()
> already prints messages in all failure paths.
So does of_register_spi_device(). And there's a dev_warn() in
of_spi_register_devices() as well...
But yes, I was also thinking of this.

Nevertheless, I added it as I thought this would keep both drivers
somehow consistent. And it's a very rare error case, though.

  Ralf
> 
>> +                       of_node_clear_flag(node, OF_POPULATED);
>> +               }
>>         }
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>
Pantelis Antoniou Oct. 17, 2016, 7:16 p.m. UTC | #3
Hi Ralf,

> On Oct 17, 2016, at 16:59 , Ralf Ramsauer <ralf@ramses-pyramidenbau.de> wrote:
> 
> Instantiated I2C device nodes are marked with OF_POPULATE. This was
> introduced in 4f001fd. On unloading, loaded device nodes will of course
> be unmarked. The problem are nodes that fail during initialisation: If a
> node fails, it won't be unloaded and hence not be unmarked.
> 
> If a I2C driver module is unloaded and reloaded, it will skip nodes that
> failed before.
> 
> Skip device nodes that are already populated and mark them only in case
> of success.
> 
> Note that the same issue exists for SPI.
> 
> Fixes: 4f001fd ("i2c: Mark instantiated device nodes with OF_POPULATE")
> Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>
> ---
> drivers/i2c/i2c-core.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 5ab6721..1704fc8 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -1681,6 +1681,7 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
> static void of_i2c_register_devices(struct i2c_adapter *adap)
> {
> 	struct device_node *bus, *node;
> +	struct i2c_client *client;
> 
> 	/* Only register child devices if the adapter has a node pointer set */
> 	if (!adap->dev.of_node)
> @@ -1695,7 +1696,14 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
> 	for_each_available_child_of_node(bus, node) {
> 		if (of_node_test_and_set_flag(node, OF_POPULATED))
> 			continue;
> -		of_i2c_register_device(adap, node);
> +
> +		client = of_i2c_register_device(adap, node);
> +		if (IS_ERR(client)) {
> +			dev_warn(&adap->dev,
> +				 "Failed to create I2C device for %s\n",
> +				 node->full_name);
> +			of_node_clear_flag(node, OF_POPULATED);
> +		}
> 	}
> 
> 	of_node_put(bus);
> @@ -2299,6 +2307,7 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
> 		if (IS_ERR(client)) {
> 			dev_err(&adap->dev, "failed to create client for '%s'\n",
> 				 rd->dn->full_name);
> +			of_node_clear_flag(rd->dn, OF_POPULATED);
> 			return notifier_from_errno(PTR_ERR(client));
> 		}
> 		break;
> -- 
> 2.10.1
> 

Thanks for this

Acked-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>

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Wolfram Sang Oct. 25, 2016, 9:23 a.m. UTC | #4
On Mon, Oct 17, 2016 at 03:59:57PM +0200, Ralf Ramsauer wrote:
> Instantiated I2C device nodes are marked with OF_POPULATE. This was
> introduced in 4f001fd. On unloading, loaded device nodes will of course
> be unmarked. The problem are nodes that fail during initialisation: If a
> node fails, it won't be unloaded and hence not be unmarked.
> 
> If a I2C driver module is unloaded and reloaded, it will skip nodes that
> failed before.
> 
> Skip device nodes that are already populated and mark them only in case
> of success.
> 
> Note that the same issue exists for SPI.
> 
> Fixes: 4f001fd ("i2c: Mark instantiated device nodes with OF_POPULATE")
> Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de>

Applied to for-current, thanks!
diff mbox

Patch

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 5ab6721..1704fc8 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1681,6 +1681,7 @@  static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 static void of_i2c_register_devices(struct i2c_adapter *adap)
 {
 	struct device_node *bus, *node;
+	struct i2c_client *client;
 
 	/* Only register child devices if the adapter has a node pointer set */
 	if (!adap->dev.of_node)
@@ -1695,7 +1696,14 @@  static void of_i2c_register_devices(struct i2c_adapter *adap)
 	for_each_available_child_of_node(bus, node) {
 		if (of_node_test_and_set_flag(node, OF_POPULATED))
 			continue;
-		of_i2c_register_device(adap, node);
+
+		client = of_i2c_register_device(adap, node);
+		if (IS_ERR(client)) {
+			dev_warn(&adap->dev,
+				 "Failed to create I2C device for %s\n",
+				 node->full_name);
+			of_node_clear_flag(node, OF_POPULATED);
+		}
 	}
 
 	of_node_put(bus);
@@ -2299,6 +2307,7 @@  static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
 		if (IS_ERR(client)) {
 			dev_err(&adap->dev, "failed to create client for '%s'\n",
 				 rd->dn->full_name);
+			of_node_clear_flag(rd->dn, OF_POPULATED);
 			return notifier_from_errno(PTR_ERR(client));
 		}
 		break;