There is a HW issue that arises when there are race conditions
between TCSS entering/exiting TC7 or TC10 states while the
driver is asserting/deasserting TCSS power request. As a
workaround, Display driver will implement a mailbox sequence
to ensure that the TCSS is in TC0 when TCSS power request is
asserted/deasserted.
The sequence is the following
1. Read mailbox command status and wait until run/busy bit is
clear
2. Write mailbox data value '1' for power request asserting
and '0' for power request deasserting
3. Write mailbox command run/busy bit and command value with 0x1
4. Read mailbox command and wait until run/busy bit is clear
before continuing power request.
while at it, let's start using struct intel_display instead of
struct drm_i915_private as well.
Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx>
Mika Kahola (2):
drm/i915/xe3lpd: Power request asserting/deasserting
drm/i915/display: Use struct intel_display instead of struct
drm_i915_private
.../gpu/drm/i915/display/intel_cx0_phy_regs.h | 8 ++++
drivers/gpu/drm/i915/display/intel_tc.c | 45 +++++++++++++++++--
2 files changed, 49 insertions(+), 4 deletions(-)
--
2.43.0
