On 2024-12-10 12:18 pm, Greg KH wrote:
On Tue, Dec 10, 2024 at 12:14:44PM +0000, Robin Murphy wrote:
On 2024-12-09 11:27 am, Sasha Levin wrote:
This is a note to let you know that I've just added the patch titled
iommu/arm-smmu: Defer probe of clients after smmu device bound
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-arm-smmu-defer-probe-of-clients-after-smmu-dev.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
FWIW the correct resolution for cherry-picking this directly is the
logically-straightforward one, as below (git is mostly just confused by
the context)
Cheers,
Robin.
----->8-----
diff --cc drivers/iommu/arm/arm-smmu/arm-smmu.c
index d6d1a2a55cc0,14618772a3d6..000000000000
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@@ -1357,10 -1435,19 +1357,21 @@@ static struct iommu_device *arm_smmu_pr
fwspec = dev_iommu_fwspec_get(dev);
if (ret)
goto out_free;
- } else {
+ } else if (fwspec && fwspec->ops == &arm_smmu_ops) {
smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode);
+
+ /*
+ * Defer probe if the relevant SMMU instance hasn't finished
+ * probing yet. This is a fragile hack and we'd ideally
+ * avoid this race in the core code. Until that's ironed
+ * out, however, this is the most pragmatic option on the
+ * table.
+ */
+ if (!smmu)
+ return ERR_PTR(dev_err_probe(dev, -EPROBE_DEFER,
+ "smmu dev has not bound yet\n"));
+ } else {
+ return ERR_PTR(-ENODEV);
}
ret = -EINVAL;a
Can you resend this in a patch that we can apply as-is?
Hope I got the tagging right :)
https://lore.kernel.org/stable/acd8068372673fb881aa9e13531470669c985519.1733834302.git.robin.murphy@xxxxxxx/
Cheers,
Robin.
thanks,
greg k-h
