Re: [PATCH v2] udmabuf: respect the device's maximum segment size

[Karl Mehltretter]

On Tue, Sep 29, 2026 at 06:00:27AM +0000, sashiko-bot@xxxxxxxxxx wrote:
> On architectures with a 256KB PAGE_SIZE (such as Hexagon or PowerPC), this
> new validation evaluates to 65536 < 262144, unconditionally returning
> -EINVAL and breaking all CPU mappings.

Right, the misc device has no dma_parms, so it gets the 64K default and
sync fails with 256K pages

The misc device has no real segment limit, so for v3 I'll give it
dma_parms with an unlimited max segment size and keep the -EINVAL for
importers that report a limit below PAGE_SIZE.

Karl