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* [PATCH v3 0/2] drm/i915/display: Power request asserting/deasserting
@ 2024-10-31 11:40 Mika Kahola
  2024-10-31 11:40 ` [PATCH v3 1/2] drm/i915/xe3lpd: " Mika Kahola
                   ` (5 more replies)
  0 siblings, 6 replies; 14+ messages in thread
From: Mika Kahola @ 2024-10-31 11:40 UTC (permalink / raw)
  To: intel-gfx; +Cc: raag.jadav, gustavo.sousa, jani.nikula, Mika Kahola

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@intel.com>

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


^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2024-11-01 11:47 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-10-31 11:40 [PATCH v3 0/2] drm/i915/display: Power request asserting/deasserting Mika Kahola
2024-10-31 11:40 ` [PATCH v3 1/2] drm/i915/xe3lpd: " Mika Kahola
2024-10-31 12:55   ` Raag Jadav
2024-10-31 14:29     ` Kahola, Mika
2024-10-31 14:50       ` Raag Jadav
2024-10-31 15:12         ` Raag Jadav
2024-11-01 11:47           ` Kahola, Mika
2024-10-31 11:40 ` [PATCH v3 2/2] drm/i915/display: Use struct intel_display instead of struct drm_i915_private Mika Kahola
2024-10-31 12:50 ` ✗ Fi.CI.CHECKPATCH: warning for drm/i915/display: Power request asserting/deasserting Patchwork
2024-10-31 12:50 ` ✗ Fi.CI.SPARSE: " Patchwork
2024-10-31 12:59 ` [PATCH v3 0/2] " Raag Jadav
2024-10-31 14:28   ` Kahola, Mika
2024-10-31 14:55     ` Raag Jadav
2024-10-31 14:04 ` ✗ Fi.CI.BAT: failure for " Patchwork

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