efe2bf9655
This is motivated by having meaningful ftrace events, but it also fixes use cases where dma_fence_is_later is called, such as in sync_file_merge. In other drivers, fence creation and cmdbuf submission normally happen atomically, mutex_lock(); fence = dma_fence_create(..., ++timeline->seqno); submit_cmdbuf(); mutex_unlock(); and have no such issue. But in our driver, because most ioctls queue commands into ctrlq, we do not want to grab a lock. Instead, we set seqno to 0 when a fence is created, and update it when the command is finally queued and the seqno is known. Signed-off-by: Chia-I Wu <olvaffe@gmail.com> Reviewed-by: Emil Velikov <emil.velikov@collabora.com> Link: http://patchwork.freedesktop.org/patch/msgid/20190429220825.156644-1-olvaffe@gmail.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.