usb: gadget: f_fs: fix DMA-BUF OUT queues

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[ Upstream commit 0145e7acd2 ]

Currently, DMA_FROM_DEVICE is used when attaching DMABUFs to IN
endpoints and DMA_TO_DEVICE for OUT endpoints. This is inverted from
how it should be.

The result is IOMMU read-only mappings placed on OUT queues,
triggering arm-smmu write faults.

Put differently, OUT endpoints flow data from host -> gadget, meaning
the UDC peripheral needs to have write access to the buffer to fill it
with the incoming data.

This commit flips the directions and updates the implicit-sync helpers
so IN endpoints act as readers and OUT endpoints as writers.

Signed-off-by: Sam Day <me@samcday.com>
Tested-by: David Heidelberg <david@ixit.cz>  # OnePlus 6T on sdm845-next-20251119
Link: https://patch.msgid.link/20260108-ffs-dmabuf-ioctl-fix-v1-2-e51633891a81@samcday.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Sam Day 2026-01-08 08:30:21 +10:00 • committed by Sasha Levin

parent 4d55fe3cd7

commit 3875c8eca2

1 changed files with 3 additions and 3 deletions

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drivers/usb/gadget/function/f_fs.c

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