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drm/i915: Program MBUS with rmw during initialization

commit c725161924 upstream.

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: 4cb4585e5a ("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 837b63e608)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228004320.127142-1-matthew.d.roper@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Matt Roper 2020-02-27 16:43:19 -08:00 committed by Greg Kroah-Hartman
parent 609b392e85
commit 2845fe63f7
1 changed files with 11 additions and 5 deletions

View File

@ -4205,13 +4205,19 @@ 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);
}