[PATCH v4 0/2] Support/debug for slow GuC loads

[Lucas De Marchi]

On Tue, Feb 27, 2024 at 05:09:54PM -0800, John.C.Harrison at Intel.com wrote:
>From: John Harrison <John.C.Harrison at Intel.com>
>
>Sometimes the GuC load is slower that it should be. For end users,
>that usually means some kind of thermal throttling issue. Internally,
>there can be any number of bugs that cause it. So don't completely
>fail to load, just cope with it and report the problem.
>
>v2: Revert include order (review feedback from Lucas)
>v3: Remove '_sysfs' from throttle file names and keep limit query in
>the same file rather than moving elsewhere (review feedback from
>Rodrigo). Fix the reporting of requested vs granted frequencies
>(review feedback from Badal).
>v4: Manually code the loop timeout/condition checking because helper
>functions are not allowed (review feedback from Lucas/Rodrigo)

wrong reason. It's not that helper functions are not allowed. Rather
*this* particular helper was considered bad and counter productive.

For similar reasons as e.g. Linus commented recently on bcachefs moving
some functions to be shared:

https://lore.kernel.org/all/CAHk-=wg3djFJMeN3L_zx3P-6eN978Y1JTssxy81RhAbxB==L8Q@mail.gmail.com/

We'd need to spend much more time cleaning it up and making it a good
interface rather than copying what we have in i915 and stuffing it in a
*utils.[hc]. In the past it turned out there were not real good reasons
for abstracting it and making it generic for all the contexts the caller
may be on.

Lucas De Marchi

>
>Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
>
>
>John Harrison (2):
>  drm/xe: Make read_perf_limit_reasons globally accessible
>  drm/xe/guc: Port over the slow GuC loading support from i915
>
> drivers/gpu/drm/xe/Makefile                   |   2 +-
> drivers/gpu/drm/xe/abi/guc_errors_abi.h       |  26 +-
> drivers/gpu/drm/xe/regs/xe_guc_regs.h         |   2 +
> drivers/gpu/drm/xe/xe_gt_freq.c               |   4 +-
> ...e_gt_throttle_sysfs.c => xe_gt_throttle.c} |  26 +-
> drivers/gpu/drm/xe/xe_gt_throttle.h           |  17 ++
> drivers/gpu/drm/xe/xe_gt_throttle_sysfs.h     |  16 --
> drivers/gpu/drm/xe/xe_guc.c                   | 226 ++++++++++++++----
> drivers/gpu/drm/xe/xe_mmio.c                  |  61 +++++
> drivers/gpu/drm/xe/xe_mmio.h                  |   2 +
> 10 files changed, 307 insertions(+), 75 deletions(-)
> rename drivers/gpu/drm/xe/{xe_gt_throttle_sysfs.c => xe_gt_throttle.c} (86%)
> create mode 100644 drivers/gpu/drm/xe/xe_gt_throttle.h
> delete mode 100644 drivers/gpu/drm/xe/xe_gt_throttle_sysfs.h
>
>-- 
>2.43.0
>