This is a note to let you know that I've just added the patch titled
drm/i915: Try to preserve the current shared_dpll for fastset on type-c ports
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-try-to-preserve-the-current-shared_dpll-for-fastset-on-type-c-ports.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ba407525f8247ee4c270369f3371b9994c27bfda Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Thu, 18 Jan 2024 16:24:36 +0200
Subject: drm/i915: Try to preserve the current shared_dpll for fastset on type-c ports
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From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
commit ba407525f8247ee4c270369f3371b9994c27bfda upstream.
Currently icl_compute_tc_phy_dplls() assumes that the active
PLL will be the TC PLL (as opposed to the TBT PLL). The actual
PLL will be selected during the modeset enable sequence, but
we need to put *something* into the crtc_state->shared_dpll
already during compute_config().
The downside of assuming one PLL or the other is that we'll
fail to fastset if the assumption doesn't match what was in
use previously. So let's instead keep the same PLL that was
in use previously (assuming there was one). This should allow
fastset to work again when using TBT PLL, at least in the
steady state.
Now, assuming we want keep the same PLL may not be entirely
correct either. But we should be covered by the type-c link
reset handling which will force a full modeset by flagging
connectors_changed=true which means the resulting modeset
can't be converted into a fastset even if the full crtc state
looks identical.
Cc: Imre Deak <imre.deak@xxxxxxxxx>
Cc: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240118142436.25928-1-ville.syrjala@xxxxxxxxxxxxxxx
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
@@ -3308,6 +3308,8 @@ static int icl_compute_tc_phy_dplls(stru
struct drm_i915_private *i915 = to_i915(state->base.dev);
struct intel_crtc_state *crtc_state =
intel_atomic_get_new_crtc_state(state, crtc);
+ const struct intel_crtc_state *old_crtc_state =
+ intel_atomic_get_old_crtc_state(state, crtc);
struct icl_port_dpll *port_dpll =
&crtc_state->icl_port_dplls[ICL_PORT_DPLL_DEFAULT];
struct skl_wrpll_params pll_params = {};
@@ -3326,7 +3328,11 @@ static int icl_compute_tc_phy_dplls(stru
return ret;
/* this is mainly for the fastset check */
- icl_set_active_port_dpll(crtc_state, ICL_PORT_DPLL_MG_PHY);
+ if (old_crtc_state->shared_dpll &&
+ old_crtc_state->shared_dpll->info->id == DPLL_ID_ICL_TBTPLL)
+ icl_set_active_port_dpll(crtc_state, ICL_PORT_DPLL_DEFAULT);
+ else
+ icl_set_active_port_dpll(crtc_state, ICL_PORT_DPLL_MG_PHY);
crtc_state->port_clock = icl_ddi_mg_pll_get_freq(i915, NULL,
&port_dpll->hw_state);
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-6.8/drm-i915-try-to-preserve-the-current-shared_dpll-for-fastset-on-type-c-ports.patch
queue-6.8/drm-i915-replace-a-memset-with-zero-initialization.patch
queue-6.8/drm-i915-add-missing-to-__assign_str-macros-in-trace.patch
queue-6.8/drm-i915-include-the-pll-name-in-the-debug-messages.patch
queue-6.8/drm-i915-suppress-old-pll-pipe_mask-checks-for-mg-tc-tbt-plls.patch
