[Intel-gfx] [PATCH 1/9] drm/i915/cmdparser: Make initialisation failure non-fatal

[Matthew Auld]

On 12 August 2016 at 16:07, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> If the developer adds a register in the wrong order, we BUG during boot.
> That makes development and testing very difficult. Let's be a bit more
> friendly and disable the command parser with a big warning if the tables
> are invalid.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_cmd_parser.c | 30 ++++++++++++++++++------------
>  drivers/gpu/drm/i915/i915_drv.h        |  2 +-
>  drivers/gpu/drm/i915/intel_engine_cs.c |  6 ++++--
>  3 files changed, 23 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
> index a1f4683f5c35..1882dc28c750 100644
> --- a/drivers/gpu/drm/i915/i915_cmd_parser.c
> +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
> @@ -746,17 +746,15 @@ static void fini_hash_table(struct intel_engine_cs *engine)
>   * Optionally initializes fields related to batch buffer command parsing in the
>   * struct intel_engine_cs based on whether the platform requires software
>   * command parsing.
> - *
> - * Return: non-zero if initialization fails
>   */
> -int intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
> +void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
>  {
>         const struct drm_i915_cmd_table *cmd_tables;
>         int cmd_table_count;
>         int ret;
>
>         if (!IS_GEN7(engine->i915))
> -               return 0;
> +               return;
>
>         switch (engine->id) {
>         case RCS:
> @@ -811,24 +809,32 @@ int intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
>                 break;
>         default:
>                 MISSING_CASE(engine->id);
> -               BUG();
> +               return;
>         }
>
> -       BUG_ON(!validate_cmds_sorted(engine, cmd_tables, cmd_table_count));
> -       BUG_ON(!validate_regs_sorted(engine));
> +       if (!hash_empty(engine->cmd_hash)) {
> +               DRM_DEBUG_DRIVER("%s: no commands?\n", engine->name);
> +               return;
> +       }
"no commands?", !hash_empty should mean we already have commands, not
that we don't, right?

With that explained or fixed:
Reviewed-by: Matthew Auld <matthew.auld at intel.com>