Hi Torsten, On Fri, 8 May 2026 at 09:42, Torsten Duwe <[email protected]> wrote: > > From: Torsten Duwe <[email protected]> > > If a device node got created dynamically, there is no guarantee that the > parent node has an associated device tree node which could specify dma > constraints. Especially PCI(e) enumeration adds intermediate "bus nodes", > also dynamically. > > Try harder to find the correct configuration by walking up the tree until > a DT association is found. > > Suggested-by: Neil Armstrong <[email protected]> > Signed-off-by: Torsten Duwe <[email protected]> > > --- > drivers/core/device.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/core/device.c b/drivers/core/device.c > index 779f371b9d5..9de64dbb3c5 100644 > --- a/drivers/core/device.c > +++ b/drivers/core/device.c > @@ -459,7 +459,19 @@ static int device_get_dma_constraints(struct udevice > *dev) > u64 size = 0; > int ret; > > - if (!CONFIG_IS_ENABLED(DM_DMA) || !parent || !dev_has_ofnode(parent)) > + if (!CONFIG_IS_ENABLED(DM_DMA) || !parent) > + return 0; > + > + /* Look for the first node in the parent chain */ > + while (parent) { > + if (dev_has_ofnode(parent)) > + break; > + > + parent = dev_get_parent(parent); > + } > + > + /* No parents have a node, bail out */ > + if (!parent) > return 0; > > /* > -- > 2.54.0 >
There's already a unit test for device_get_dma_constraints() in test/dm/read.c (dm_test_dma_ranges). Since you are extending it to walk past nodes without an ofnode, please can you add a case exercising the new path - a sandbox device whose immediate parent has no DT reference should do it. Regards, Simon
