On Wed, Mar 05, 2025 at 02:49:46PM +0000, Sebastian Brzezinka wrote:
> This reverts commit 0ddae025ab6cefa9aba757da3cd1d27908d70b0e.
>
> According to bspec 14181, CACHE_MODE_0 is a register that's under userspace
> control, and DISABLE_REPACKING_FOR_COMPRESSION workaround should be already
> in all recent Mesa releases. So, there is no need to include it in kernel.
igt doesn't have it.
>
> Also, this workaround·sporadically fails to load:
> ```
> ERROR GT0: engine workaround lost on application! (reg[7000]=0x0,
> relevant bits were 0x0 vs expected 0x8000)
> ```
If it somehow fails to load from the kernel why would it
work from userspace?
Hmm, apparently CACHE_MODE_0 needs the mcr steering stuff.
Does that fix the verification fail?
>
> Signed-off-by: Sebastian Brzezinka <sebastian.brzezinka@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_gt_regs.h | 1 -
> drivers/gpu/drm/i915/gt/intel_workarounds.c | 9 ---------
> 2 files changed, 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 7421ed18d8d1..52ddfa9f3ad3 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -440,7 +440,6 @@
> #define XEHPG_INSTDONE_GEOM_SVG MCR_REG(0x666c)
>
> #define CACHE_MODE_0_GEN7 _MMIO(0x7000) /* IVB+ */
> -#define DISABLE_REPACKING_FOR_COMPRESSION REG_BIT(15) /* jsl+ */
> #define RC_OP_FLUSH_ENABLE (1 << 0)
> #define HIZ_RAW_STALL_OPT_DISABLE (1 << 2)
> #define CACHE_MODE_1 _MMIO(0x7004) /* IVB+ */
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 116683ebe074..51839f270d57 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -2306,15 +2306,6 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
> GEN8_RC_SEMA_IDLE_MSG_DISABLE);
> }
>
> - if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) {
> - /*
> - * "Disable Repacking for Compression (masked R/W access)
> - * before rendering compressed surfaces for display."
> - */
> - wa_masked_en(wal, CACHE_MODE_0_GEN7,
> - DISABLE_REPACKING_FOR_COMPRESSION);
> - }
> -
> if (GRAPHICS_VER(i915) == 11) {
> /* This is not an Wa. Enable for better image quality */
> wa_masked_en(wal,
> --
> 2.34.1
--
Ville Syrjälä
Intel
