On 3/31/2017 1:40 PM, Russell King - ARM Linux wrote:
> Ping, this issue still exists with 4.11-rc4 - and there's been no
> reaction from the alleged CAAM maintainers.
>
Sorry, this somehow slipped through (Cc vs. To, no linux-crypto).
> On Tue, Aug 09, 2016 at 11:48:38AM -0500, Rob Herring wrote:
>> On Tue, Aug 9, 2016 at 4:33 AM, Russell King <rmk+kernel at armlinux.org.uk> wrote:
>>> When a Linux device is released and cleaned up, we left the OF device
>>> node marked as populated. This causes the Freescale CAAM driver
>>> (drivers/crypto/caam) problems when the module is removed and re-
>>> inserted:
>>>
>>> JR0 Platform device creation error
>>> JR0 Platform device creation error
>>> caam 2100000.caam: no queues configured, terminating
>>> caam: probe of 2100000.caam failed with error -12
>>>
>>> The reason is that CAAM creates platform devices for each job ring:
>>>
>>> for_each_available_child_of_node(nprop, np)
>>> if (of_device_is_compatible(np, "fsl,sec-v4.0-job-ring") ||
>>> of_device_is_compatible(np, "fsl,sec4.0-job-ring")) {
>>> ctrlpriv->jrpdev[ring] =
>>> of_platform_device_create(np, NULL, dev);
>>>
>>> which sets OF_POPULATED on the device node, but then it cleans these
>>> up:
>>>
>>> /* Remove platform devices for JobRs */
>>> for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
>>> if (ctrlpriv->jrpdev[ring])
>>> of_device_unregister(ctrlpriv->jrpdev[ring]);
>>
>> This looks a bit asymmetrical to me with a of_platform_device_* call
>> and a of_device_* call.
>>
>> I think you could use of_platform_{de}populate here instead. That
>> would simplify things in the driver a bit too as you wouldn't need to
>> store jrpdev. It wouldn't work if there are other child nodes with
Indeed, this would clean-up the driver a bit. However, the driver needs
to know how many of the devices probed successfully - to print the
number and more importantly to exit in case total_jobrs = 0.
Thus, I would keep the one-by-one probing of the devices.
What options are there in this case?
Should a function symmetric to of_platform_device_create() be added - to
replace of_device_unregister() - or rely on an open-coded solution?
Thanks,
Horia
>> compatible strings which you don't want devices created.
>>
>>> }
>>>
>>> which leaves OF_POPULATED set.
>>>
>>> Arrange for platform devices with a device node to clear the
>>> OF_POPULATED bit when they are released.
>>>
>>> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
>>> ---
>>> Please check this carefully - it may have issues where an of_node
>>> pointer is copied from one platform device to another, but IMHO
>>> doing that is itself buggy behaviour.
>>
>> Agreed, that is wrong.
>>
>>>
>>> Resending due to wrong list address, sorry.
>>>
>>> include/linux/of_device.h | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
>>> index cc7dd687a89d..7a8362d0c6d2 100644
>>> --- a/include/linux/of_device.h
>>> +++ b/include/linux/of_device.h
>>> @@ -43,6 +43,7 @@ extern int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env
>>>
>>> static inline void of_device_node_put(struct device *dev)
>>> {
>>> + of_node_clear_flag(dev->of_node, OF_POPULATED);
>>
>> This would result in clearing the flag twice in the
>> of_platform_populate/of_platform_depopulate case. It would do the same
>> for other bus types like i2c as well. That doesn't really hurt
>> anything that I can think of, but just not the best implementation. I
>> think adding a of_platform_device_unregister() call that wraps
>> of_platform_device_destroy would be more balanced.
>>
>> I looked thru all the callers of of_platform_device_create. The only
>> other ones affected by this are:
>>
>> drivers/macintosh/ams/ams-core.c
>> drivers/macintosh/therm_adt746x.c
>> drivers/macintosh/therm_windtunnel.c
>>
>> The others either have no remove path or a buggy remove path.
>>
>> Rob
>