[Linaro-mm-sig] Re: [PATCH v2 0/3] usb: gadget: functionfs: DMABUF import interface

Hi Paul,

W dniu 22.03.2023 o 10:21, Paul Cercueil pisze:

Hi,

This small patchset adds three new IOCTLs that can be used to attach, detach, or transfer from/to a DMABUF object.

Changes since v1:

• patch [2/3] is new. I had to reuse a piece of code that was already duplicated in the driver, so I factorized the code.
• Make ffs_dma_resv_lock() static
• Add MODULE_IMPORT_NS(DMA_BUF);
• The attach/detach functions are now performed without locking the eps_lock spinlock. The transfer function starts with the spinlock unlocked, then locks it before allocating and queueing the USB transfer.

Can you share an example use case for these new features? Is there a userspace that excercises the new ioctls?

Regards,

Andrzej