On 09/04/18 16:44, Heiko St?bner wrote: > Hi Tomeu, > > Am Montag, 9. April 2018, 16:41:56 CEST schrieb Tomeu Vizoso: >> in today's linux-next, the DRM driver fails to probe because the iommu >> driver fails to find the aclk. I need to apply this patch for things >> to work again. > > Thanks for catching that issue. > > This seems to expose a backwards-compatibility issue, as this breaks > all old devicetrees, so should get a proper fix, apart from me applying > the dt-patch I missed. > > Looking at the iommu-clock-handling patch, I imagine this part as > the culprit: > > + iommu->num_clocks = ARRAY_SIZE(rk_iommu_clocks); > + iommu->clocks = devm_kcalloc(iommu->dev, iommu->num_clocks, > + sizeof(*iommu->clocks), GFP_KERNEL); > + if (!iommu->clocks) > + return -ENOMEM; > > The clk-bulk functions seem to work with simple for loops and > should (as the other standard clock functions) just work fine with > an empty struct, so I guess a simple > > if (!iommu->clocks && iommu->num_clocks > 0) > return -ENOMEM; > > should hopefully be enough. I'll try to give this a test later on > if nobody beats me to it :-) But iommu->num_clocks is clearly set to a nonzero compile-time constant at this point ;) I'd assume it's the return from devm_clk_bulk_get() which needs to special-case the "no clocks found" case from any other error, and *then* blat num_clocks to 0 if so. Robin.
