Messages in this thread | | | Subject | Re: [PATCH v3 9/9] xen/gntdev: Implement dma-buf import functionality | From | Oleksandr Andrushchenko <> | Date | Thu, 14 Jun 2018 09:39:34 +0300 |
| |
On 06/14/2018 01:03 AM, Boris Ostrovsky wrote: > On 06/13/2018 05:04 AM, Oleksandr Andrushchenko wrote: >> On 06/13/2018 06:14 AM, Boris Ostrovsky wrote: >>> >>> On 06/12/2018 09:42 AM, Oleksandr Andrushchenko wrote: >>> >>>> int gntdev_dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 >>>> fd) >>>> { >>>> - return -EINVAL; >>>> + struct gntdev_dmabuf *gntdev_dmabuf; >>>> + struct dma_buf_attachment *attach; >>>> + struct dma_buf *dma_buf; >>>> + >>>> + gntdev_dmabuf = dmabuf_imp_find_unlink(priv, fd); >>>> + if (IS_ERR(gntdev_dmabuf)) >>>> + return PTR_ERR(gntdev_dmabuf); >>>> + >>>> + pr_debug("Releasing DMA buffer with fd %d\n", fd); >>>> + >>>> + attach = gntdev_dmabuf->u.imp.attach; >>>> + >>>> + if (gntdev_dmabuf->u.imp.sgt) >>>> + dma_buf_unmap_attachment(attach, gntdev_dmabuf->u.imp.sgt, >>>> + DMA_BIDIRECTIONAL); >>>> + dma_buf = attach->dmabuf; >>>> + dma_buf_detach(attach->dmabuf, attach); >>>> + dma_buf_put(dma_buf); >>>> + >>>> + dmabuf_imp_end_foreign_access(gntdev_dmabuf->u.imp.refs, >>>> + gntdev_dmabuf->nr_pages); >>> >>> >>> Should you first end foreign access, before doing anything? >>> >> I am rolling back in reverse order here, so I think we first need >> to finish local activities with the buffer and then end foreign >> access. > Looking at gntdev_dmabuf_imp_to_refs(), the order is > dmabuf_imp_alloc_storage() > dma_buf_attach() > dma_buf_map_attachment() > dmabuf_imp_grant_foreign_access() > > Or was I looking at wrong place? Agree, will move as you suggest > -boris
| |