diff options
Diffstat (limited to 'Documentation/sync_file.txt')
| -rw-r--r-- | Documentation/sync_file.txt | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/Documentation/sync_file.txt b/Documentation/sync_file.txt index c3d033a06e8d..496fb2c3b3e6 100644 --- a/Documentation/sync_file.txt +++ b/Documentation/sync_file.txt @@ -1,8 +1,8 @@ - Sync File API Guide - ~~~~~~~~~~~~~~~~~~~ +=================== +Sync File API Guide +=================== - Gustavo Padovan - <gustavo at padovan dot org> +:Author: Gustavo Padovan <gustavo at padovan dot org> This document serves as a guide for device drivers writers on what the sync_file API is, and how drivers can support it. Sync file is the carrier of @@ -46,16 +46,17 @@ Creating Sync Files When a driver needs to send an out-fence userspace it creates a sync_file. -Interface: +Interface:: + struct sync_file *sync_file_create(struct dma_fence *fence); The caller pass the out-fence and gets back the sync_file. That is just the first step, next it needs to install an fd on sync_file->file. So it gets an -fd: +fd:: fd = get_unused_fd_flags(O_CLOEXEC); -and installs it on sync_file->file: +and installs it on sync_file->file:: fd_install(fd, sync_file->file); @@ -71,7 +72,8 @@ When userspace needs to send an in-fence to the driver it passes file descriptor of the Sync File to the kernel. The kernel can then retrieve the fences from it. -Interface: +Interface:: + struct dma_fence *sync_file_get_fence(int fd); @@ -79,5 +81,6 @@ The returned reference is owned by the caller and must be disposed of afterwards using dma_fence_put(). In case of error, a NULL is returned instead. References: -[1] struct sync_file in include/linux/sync_file.h -[2] All interfaces mentioned above defined in include/linux/sync_file.h + +1. struct sync_file in include/linux/sync_file.h +2. All interfaces mentioned above defined in include/linux/sync_file.h |