diff options
| author | Imre Deak <imre.deak@intel.com> | 2016-05-03 15:54:21 +0300 |
|---|---|---|
| committer | Imre Deak <imre.deak@intel.com> | 2016-05-03 16:49:19 +0300 |
| commit | 450174fe9cc6a1fbc357984f2436ca5fd9960c31 (patch) | |
| tree | c56e19d33d53d31b03d7aa1cde5418f62c461ed1 /drivers/gpu/drm/i915/i915_reg.h | |
| parent | 36579cb63b87b7a4406b9b19c8ff376ca701083b (diff) | |
drm/i915/chv: Tune L3 SQC credits based on actual latencies
While browsing BSpec I bumped into a note saying we need to tune these
values based on actual measurements done after initial enabling. I've
checked that it indeed improves things on BXT. I haven't checked this on
CHV, but here it is if someone wants to give it a go.
v2:
- Add note about the discrepancy wrt. to the spec in the formula
calculating the credit encodings. (Mika, Ville)
- Move the WA comment to the new function. (Ville)
v3:
- Keep the comment about the SQC WA in the caller. (Ville)
CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462280061-1457-4-git-send-email-imre.deak@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/i915_reg.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_reg.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 543f440a163e..54ce0b105956 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -6091,6 +6091,12 @@ enum skl_disp_power_wells { #define VLV_B0_WA_L3SQCREG1_VALUE 0x00D30000 #define GEN8_L3SQCREG1 _MMIO(0xB100) +/* + * Note that on CHV the following has an off-by-one error wrt. to BSpec. + * Using the formula in BSpec leads to a hang, while the formula here works + * fine and matches the formulas for all other platforms. A BSpec change + * request has been filed to clarify this. + */ #define L3_GENERAL_PRIO_CREDITS(x) (((x) >> 1) << 19) #define L3_HIGH_PRIO_CREDITS(x) (((x) >> 1) << 14) |