diff mbox series

[RFC] i2c: skip of_i2c_register_device() for invalid child nodes

Message ID 20241030010723.3520941-1-quic_abhinavk@quicinc.com
State Under Review
Delegated to: Andi Shyti
Headers show
Series [RFC] i2c: skip of_i2c_register_device() for invalid child nodes | expand

Commit Message

Abhinav Kumar Oct. 30, 2024, 1:07 a.m. UTC
of_i2c_register_devices() adds all child nodes of a given i2c bus
however in certain device trees of_alias_from_compatible() and
of_property_read_u32() can fail as the child nodes of the device
might not be valid i2c client devices. One such example is the
i2c aux device for the DRM MST toplogy manager which uses the
display controller device node to add the i2c adaptor [1] leading
to an error spam like below

i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
i2c i2c-20: of_i2c: modalias failure on /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
i2c i2c-20: of_i2c: invalid reg on /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table

Add protection against invalid child nodes before trying to register
i2c devices for all child nodes.

[1] : https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/display/drm_dp_mst_topology.c#L5985

Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
---
 drivers/i2c/i2c-core-of.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Dmitry Baryshkov Oct. 31, 2024, 6:23 p.m. UTC | #1
On Wed, 30 Oct 2024 at 03:07, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>
> of_i2c_register_devices() adds all child nodes of a given i2c bus
> however in certain device trees of_alias_from_compatible() and
> of_property_read_u32() can fail as the child nodes of the device
> might not be valid i2c client devices. One such example is the
> i2c aux device for the DRM MST toplogy manager which uses the
> display controller device node to add the i2c adaptor [1] leading
> to an error spam like below
>
> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> i2c i2c-20: of_i2c: modalias failure on /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
> i2c i2c-20: of_i2c: invalid reg on /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>
> Add protection against invalid child nodes before trying to register
> i2c devices for all child nodes.
>
> [1] : https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/display/drm_dp_mst_topology.c#L5985
>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>  drivers/i2c/i2c-core-of.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
> index a6c407d36800..62a2603c3092 100644
> --- a/drivers/i2c/i2c-core-of.c
> +++ b/drivers/i2c/i2c-core-of.c
> @@ -86,6 +86,8 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>  {
>         struct device_node *bus, *node;
>         struct i2c_client *client;
> +       u32 addr;
> +       char temp[16];
>
>         /* Only register child devices if the adapter has a node pointer set */
>         if (!adap->dev.of_node)
> @@ -101,6 +103,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>                 if (of_node_test_and_set_flag(node, OF_POPULATED))
>                         continue;
>
> +               if (of_property_read_u32(node, "reg", &addr) ||
> +                   of_alias_from_compatible(node, temp, sizeof(temp)))
> +                       continue;

I think just of_property_read_u32() should be enough to skip
non-I2C-device children. If of_alias_from_compatible() fails, it is a
legit error.

> +
>                 client = of_i2c_register_device(adap, node);
>                 if (IS_ERR(client)) {
>                         dev_err(&adap->dev,
> --
> 2.34.1
>
Abhinav Kumar Oct. 31, 2024, 6:45 p.m. UTC | #2
On 10/31/2024 11:23 AM, Dmitry Baryshkov wrote:
> On Wed, 30 Oct 2024 at 03:07, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>>
>> of_i2c_register_devices() adds all child nodes of a given i2c bus
>> however in certain device trees of_alias_from_compatible() and
>> of_property_read_u32() can fail as the child nodes of the device
>> might not be valid i2c client devices. One such example is the
>> i2c aux device for the DRM MST toplogy manager which uses the
>> display controller device node to add the i2c adaptor [1] leading
>> to an error spam like below
>>
>> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>> i2c i2c-20: of_i2c: modalias failure on /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>> i2c i2c-20: of_i2c: invalid reg on /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>>
>> Add protection against invalid child nodes before trying to register
>> i2c devices for all child nodes.
>>
>> [1] : https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/display/drm_dp_mst_topology.c#L5985
>>
>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>> ---
>>   drivers/i2c/i2c-core-of.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
>> index a6c407d36800..62a2603c3092 100644
>> --- a/drivers/i2c/i2c-core-of.c
>> +++ b/drivers/i2c/i2c-core-of.c
>> @@ -86,6 +86,8 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>>   {
>>          struct device_node *bus, *node;
>>          struct i2c_client *client;
>> +       u32 addr;
>> +       char temp[16];
>>
>>          /* Only register child devices if the adapter has a node pointer set */
>>          if (!adap->dev.of_node)
>> @@ -101,6 +103,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>>                  if (of_node_test_and_set_flag(node, OF_POPULATED))
>>                          continue;
>>
>> +               if (of_property_read_u32(node, "reg", &addr) ||
>> +                   of_alias_from_compatible(node, temp, sizeof(temp)))
>> +                       continue;
> 
> I think just of_property_read_u32() should be enough to skip
> non-I2C-device children. If of_alias_from_compatible() fails, it is a
> legit error.
> 

Thanks for the review.

of_alias_from_compatible() looks for a compatible string but all child 
nodes such as ports will not have the compatible. Hence below error will 
still be seen:

i2c i2c-20: of_i2c: modalias failure on 
/soc@0/display-subsystem@ae00000/display-controller@ae01000/ports

>> +
>>                  client = of_i2c_register_device(adap, node);
>>                  if (IS_ERR(client)) {
>>                          dev_err(&adap->dev,
>> --
>> 2.34.1
>>
> 
>
Dmitry Baryshkov Oct. 31, 2024, 7:30 p.m. UTC | #3
On Thu, Oct 31, 2024 at 11:45:53AM -0700, Abhinav Kumar wrote:
> 
> 
> On 10/31/2024 11:23 AM, Dmitry Baryshkov wrote:
> > On Wed, 30 Oct 2024 at 03:07, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
> > > 
> > > of_i2c_register_devices() adds all child nodes of a given i2c bus
> > > however in certain device trees of_alias_from_compatible() and
> > > of_property_read_u32() can fail as the child nodes of the device
> > > might not be valid i2c client devices. One such example is the
> > > i2c aux device for the DRM MST toplogy manager which uses the
> > > display controller device node to add the i2c adaptor [1] leading
> > > to an error spam like below
> > > 
> > > i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> > > i2c i2c-20: of_i2c: modalias failure on /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> > > i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> > > i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
> > > i2c i2c-20: of_i2c: invalid reg on /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
> > > i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
> > > 
> > > Add protection against invalid child nodes before trying to register
> > > i2c devices for all child nodes.
> > > 
> > > [1] : https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/display/drm_dp_mst_topology.c#L5985
> > > 
> > > Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> > > ---
> > >   drivers/i2c/i2c-core-of.c | 6 ++++++
> > >   1 file changed, 6 insertions(+)
> > > 
> > > diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
> > > index a6c407d36800..62a2603c3092 100644
> > > --- a/drivers/i2c/i2c-core-of.c
> > > +++ b/drivers/i2c/i2c-core-of.c
> > > @@ -86,6 +86,8 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
> > >   {
> > >          struct device_node *bus, *node;
> > >          struct i2c_client *client;
> > > +       u32 addr;
> > > +       char temp[16];
> > > 
> > >          /* Only register child devices if the adapter has a node pointer set */
> > >          if (!adap->dev.of_node)
> > > @@ -101,6 +103,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
> > >                  if (of_node_test_and_set_flag(node, OF_POPULATED))
> > >                          continue;
> > > 
> > > +               if (of_property_read_u32(node, "reg", &addr) ||
> > > +                   of_alias_from_compatible(node, temp, sizeof(temp)))
> > > +                       continue;
> > 
> > I think just of_property_read_u32() should be enough to skip
> > non-I2C-device children. If of_alias_from_compatible() fails, it is a
> > legit error.
> > 
> 
> Thanks for the review.
> 
> of_alias_from_compatible() looks for a compatible string but all child nodes
> such as ports will not have the compatible. Hence below error will still be
> seen:
> 
> i2c i2c-20: of_i2c: modalias failure on
> /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports

But ports node don't have a reg property too, so it should be skipped
based on that.

> 
> > > +
> > >                  client = of_i2c_register_device(adap, node);
> > >                  if (IS_ERR(client)) {
> > >                          dev_err(&adap->dev,
> > > --
> > > 2.34.1
> > > 
> > 
> >
Abhinav Kumar Oct. 31, 2024, 8:34 p.m. UTC | #4
On 10/31/2024 12:30 PM, Dmitry Baryshkov wrote:
> On Thu, Oct 31, 2024 at 11:45:53AM -0700, Abhinav Kumar wrote:
>>
>>
>> On 10/31/2024 11:23 AM, Dmitry Baryshkov wrote:
>>> On Wed, 30 Oct 2024 at 03:07, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>>>>
>>>> of_i2c_register_devices() adds all child nodes of a given i2c bus
>>>> however in certain device trees of_alias_from_compatible() and
>>>> of_property_read_u32() can fail as the child nodes of the device
>>>> might not be valid i2c client devices. One such example is the
>>>> i2c aux device for the DRM MST toplogy manager which uses the
>>>> display controller device node to add the i2c adaptor [1] leading
>>>> to an error spam like below
>>>>
>>>> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>>>> i2c i2c-20: of_i2c: modalias failure on /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>>>> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
>>>> i2c i2c-20: of_i2c: register /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>>>> i2c i2c-20: of_i2c: invalid reg on /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>>>> i2c i2c-20: Failed to create I2C device for /soc@0/display-subsystem@ae00000/display-controller@ae01000/opp-table
>>>>
>>>> Add protection against invalid child nodes before trying to register
>>>> i2c devices for all child nodes.
>>>>
>>>> [1] : https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/display/drm_dp_mst_topology.c#L5985
>>>>
>>>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>>> ---
>>>>    drivers/i2c/i2c-core-of.c | 6 ++++++
>>>>    1 file changed, 6 insertions(+)
>>>>
>>>> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
>>>> index a6c407d36800..62a2603c3092 100644
>>>> --- a/drivers/i2c/i2c-core-of.c
>>>> +++ b/drivers/i2c/i2c-core-of.c
>>>> @@ -86,6 +86,8 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>>>>    {
>>>>           struct device_node *bus, *node;
>>>>           struct i2c_client *client;
>>>> +       u32 addr;
>>>> +       char temp[16];
>>>>
>>>>           /* Only register child devices if the adapter has a node pointer set */
>>>>           if (!adap->dev.of_node)
>>>> @@ -101,6 +103,10 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>>>>                   if (of_node_test_and_set_flag(node, OF_POPULATED))
>>>>                           continue;
>>>>
>>>> +               if (of_property_read_u32(node, "reg", &addr) ||
>>>> +                   of_alias_from_compatible(node, temp, sizeof(temp)))
>>>> +                       continue;
>>>
>>> I think just of_property_read_u32() should be enough to skip
>>> non-I2C-device children. If of_alias_from_compatible() fails, it is a
>>> legit error.
>>>
>>
>> Thanks for the review.
>>
>> of_alias_from_compatible() looks for a compatible string but all child nodes
>> such as ports will not have the compatible. Hence below error will still be
>> seen:
>>
>> i2c i2c-20: of_i2c: modalias failure on
>> /soc@0/display-subsystem@ae00000/display-controller@ae01000/ports
> 
> But ports node don't have a reg property too, so it should be skipped
> based on that.
> 

hmmm this is a good point. I see that individual port@ nodes do have a 
reg but ports node does not.

I will re-test this once without the of_alias_from_compatible() and drop 
the of_alias_from_compatible in v2.

>>
>>>> +
>>>>                   client = of_i2c_register_device(adap, node);
>>>>                   if (IS_ERR(client)) {
>>>>                           dev_err(&adap->dev,
>>>> --
>>>> 2.34.1
>>>>
>>>
>>>
>
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index a6c407d36800..62a2603c3092 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -86,6 +86,8 @@  void of_i2c_register_devices(struct i2c_adapter *adap)
 {
 	struct device_node *bus, *node;
 	struct i2c_client *client;
+	u32 addr;
+	char temp[16];
 
 	/* Only register child devices if the adapter has a node pointer set */
 	if (!adap->dev.of_node)
@@ -101,6 +103,10 @@  void of_i2c_register_devices(struct i2c_adapter *adap)
 		if (of_node_test_and_set_flag(node, OF_POPULATED))
 			continue;
 
+		if (of_property_read_u32(node, "reg", &addr) ||
+		    of_alias_from_compatible(node, temp, sizeof(temp)))
+			continue;
+
 		client = of_i2c_register_device(adap, node);
 		if (IS_ERR(client)) {
 			dev_err(&adap->dev,