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Subject: Re: [PATCH v2 0/3] usb: gadget: functionfs: DMABUF import interface
To:     Paul Cercueil <paul@crapouillou.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
Cc:     michael.hennerich@analog.com, nuno.sa@analog.com,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linaro-mm-sig@lists.linaro.org
References: <20230322092118.9213-1-paul@crapouillou.net>
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From:   Andrzej Pietrasiewicz <andrzej.p@collabora.com>
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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