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drm/i915: Program MBUS with rmw during initialization

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It wasn't terribly clear from the bspec's wording, but after discussion
with the hardware folks, it turns out that we need to preserve the
pre-existing contents of the MBUS ABOX control register when
initializing a few specific bits.

Bspec: 49213
Bspec: 50096
Fixes: 4cb4585e5a7f ("drm/i915/icl: initialize MBus during display init")
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200204011032.582737-1-matthew.d.roper@intel.com
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
(cherry picked from commit 837b63e6087838d0f1e612d448405419199d8033)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228004320.127142-1-matthew.d.roper@intel.com
This commit is contained in:
Matt Roper 2020-02-27 16:43:19 -08:00 committed by Jani Nikula
parent 33e059a2e4
commit c725161924
1 changed files with 11 additions and 5 deletions
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16
drivers/gpu/drm/i915/display/intel_display_power.c
View File

@ -4466,13 +4466,19 @@ static void icl_dbuf_disable(struct drm_i915_private *dev_priv)
static void icl_mbus_init(struct drm_i915_private *dev_priv)
{
u32 val;
u32 mask, val;
val = MBUS_ABOX_BT_CREDIT_POOL1(16) |
MBUS_ABOX_BT_CREDIT_POOL2(16) |
MBUS_ABOX_B_CREDIT(1) |
MBUS_ABOX_BW_CREDIT(1);
mask = MBUS_ABOX_BT_CREDIT_POOL1_MASK |
MBUS_ABOX_BT_CREDIT_POOL2_MASK |
MBUS_ABOX_B_CREDIT_MASK |
MBUS_ABOX_BW_CREDIT_MASK;
val = I915_READ(MBUS_ABOX_CTL);
val &= ~mask;
val |= MBUS_ABOX_BT_CREDIT_POOL1(16) |
MBUS_ABOX_BT_CREDIT_POOL2(16) |
MBUS_ABOX_B_CREDIT(1) |
MBUS_ABOX_BW_CREDIT(1);
I915_WRITE(MBUS_ABOX_CTL, val);
}