I'd swapped the operands, so if we weren't in lockstep with the hardware we
said the sequence was always passed. Additionally, a race was available that
we might have failed at recovering from. Instead, I've replaced the logic
with new stuff that should be more robust and not rely on all the parties in
userland following the same IRQ_EMIT() == 1 protocol. Also, in a radical
departure from past efforts, include a long comment describing the failure
modes and how we're working around them.
Thanks to haihao for catching the original issue.
dri_bufmgr.h is replaced by intel_bufmgr.h, and several functions are renamed,
though the structures and many functions remain dri_bufmgr_* and dri_bo_*
When a software fallback has completed, usermode must notify the kernel so
that any scanout buffers can be synchronized. This ioctl should be called
whenever a fallback completes to flush CPU and chipset caches.
Thanks to Thomas Hellstrom for catching the issue, no thanks to the kernel
developer who authoritatively told me that they would get restarted on their
own.
This is the create (may want location flags), pread/pwrite/mmap
(performance tuning hints), and set_domain (will 32 bits be enough for
everyone?) ioctls. Left in the generic set are just flink/open/close.
The 2D driver must be updated for this change, and API but not ABI is broken
for 3D. The driver version is bumped to mark this.
The code was discarding the dri_bo_gem structure and saving only the kernel
handle. This lost the mmap address, causing pain when the next buffer user
wanted to map the buffer.
Eric Anholt
Xiang, Haihao
Kristian Høgsberg
Matthieu Herrb
Keith Packard