Hi Joerg,
On 2018-12-19 15:34, Joerg Roedel wrote:
> Hi Marek,
>
> thanks for the report!
>
> On Wed, Dec 19, 2018 at 10:54:18AM +0100, Marek Szyprowski wrote:
>> On 2018-12-11 16:05, Joerg Roedel wrote:
>>> From: Joerg Roedel <jroe...@suse.de>
>>>
>>> Make sure to invoke this call-back through the proper
>>> function of the IOMMU-API.
>>>
>>> Signed-off-by: Joerg Roedel <jroe...@suse.de>
>>> ---
>>> drivers/iommu/of_iommu.c | 6 +++---
>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
>>> index c5dd63072529..4d4847de727e 100644
>>> --- a/drivers/iommu/of_iommu.c
>>> +++ b/drivers/iommu/of_iommu.c
>>> @@ -218,10 +218,10 @@ const struct iommu_ops *of_iommu_configure(struct
>>> device *dev,
>>> ops = dev->iommu_fwspec->ops;
>>> /*
>>> * If we have reason to believe the IOMMU driver missed the initial
>>> - * add_device callback for dev, replay it to get things in order.
>>> + * probe for dev, replay it to get things in order.
>>> */
>>> - if (ops && ops->add_device && dev->bus && !dev->iommu_group)
>>> - err = ops->add_device(dev);
>>> + if (dev->bus && !dev->iommu_group)
>>> + err = iommu_probe_device(dev);
>> This change removes a check for NULL ops, what causes NULL pointer
>> exception on first device without IOMMU.
> Bummer, this check was supposed to be in iommu_probe_device(), but
> apparently it got lost. Does the attached patch fix it?
Yes, it fixes this issue.
>> I'm also not sure if this is a good idea to call iommu_probe_device(),
>> which comes from dev->bus->iommu_ops, which might be different from ops
>> from local variable.
> The local variable comes from dev->iommu_fwspec->ops, which should be
> exactly the same as dev->bus->iommu_ops. I'll leave that for now until
> it turns out to be a problem (which I don't expect).
>
>
> Regards,
>
> Joerg
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index a2131751dcff..3ed4db334341 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -114,10 +114,14 @@ void iommu_device_unregister(struct iommu_device *iommu)
> int iommu_probe_device(struct device *dev)
> {
> const struct iommu_ops *ops = dev->bus->iommu_ops;
> + int ret = -EINVAL;
>
> WARN_ON(dev->iommu_group);
>
> - return ops->add_device(dev);
> + if (ops)
> + ret = ops->add_device(dev);
> +
> + return ret;
> }
>
> void iommu_release_device(struct device *dev)
>
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
