Re: [PATCH v2 00/28] Replace seqno values with request structures

Daniel Vetter
2014-11-19T19:28:35Z

On Fri, Nov 14, 2014 at 12:18:51PM +0000, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> There is a general feeling that it is better to move away from using a simple
> integer 'seqno' value to track batch buffer completion. Instead, the request
> structure should be used. That provides for much more flexibility going
> forwards. Especially which things like a GPU scheduler (which can re-order batch
> buffers and hence seqnos after submission to the hardware), Android sync points
> and other such features which potentially make seqno usage more and more
> complex.
>
> This patch set does the work of converting most of the driver to use request
> structures in preference to seqno values. The only place left that still uses
> seqnos is the semaphore code. It was decided to leave that alone for the time
> being as the semaphores are hardware based and the hardware only understands
> seqno values.
>
> v2: Rebased to newer nightly tree which significantly changed some of the
> display MMIO flip code (including making __wait_request public and renaming
> it).
>
> [Patches against drm-intel-nightly tree fetched 13/11/2014]
>
> John Harrison (28):
> drm/i915: Ensure OLS & PLR are always in sync
> drm/i915: Add reference count to request structure
> drm/i915: Add helper functions to aid seqno -> request transition
> drm/i915: Replace last_[rwf]_seqno with last_[rwf]_req
> drm/i915: Convert i915_gem_ring_throttle to use requests
> drm/i915: Ensure requests stick around during waits
> drm/i915: Remove 'outstanding_lazy_seqno'
> drm/i915: Make 'i915_gem_check_olr' actually check by request not seqno
> drm/i915: Convert 'last_flip_req' to be a request not a seqno
> drm/i915: Convert i915_wait_seqno to i915_wait_request
> drm/i915: Add IRQ friendly request deference facility
> drm/i915: Convert mmio_flip::seqno to struct request
> drm/i915: Convert __wait_seqno() to __wait_request()
> drm/i915: Remove obsolete seqno parameter from 'i915_add_request'
> drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'
> drm/i915: Convert trace functions from seqno to request
> drm/i915: Convert 'trace_irq' to use requests rather than seqnos
> drm/i915: Convert 'ring_idle()' to use requests not seqnos
> drm/i915: Connect requests to rings at creation not submission
> drm/i915: Convert 'i915_seqno_passed' calls into 'i915_gem_request_completed'
> drm/i915: Remove the now redundant 'obj->ring'
> drm/i915: Cache request completion status
> drm/i915: Zero fill the request structure
> drm/i915: Spinlock protection for request list
> drm/i915: Interrupt driven request completion
> drm/i915: Remove obsolete parameter to i915_gem_request_completed()
> drm/i915: Add unique id to the request structure for debugging
> drm/i915: Additional request structure tracing

Erhm this stuff is blocking refactoring work since I don't want to wreak
major havoc with the codebase to avoid rebase hell for you. That means
reviewing and merging early, even if the tail of the patch series isn't
100% clear yet.

Imo everything past patch 21 is fairly optional icing on the cake here.
And if there early patches are non-controversial then I'd like them to
pull in even if there's some detail missing in a patch in the middle.

But I haven't seen r-b tags anywhere really :(

Or am I blind?

Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch