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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
commit | 3565071f226432336a54d0193d729fa4508a3394 (patch) | |
tree | 4cde13f078f84c0a7785d234fd52edce7c90546a /debian/patches-rt/0004-drm-i915-Don-t-disable-interrupts-on-PREEMPT_RT-duri.patch | |
parent | Adding upstream version 6.6.15. (diff) | |
download | linux-3565071f226432336a54d0193d729fa4508a3394.tar.xz linux-3565071f226432336a54d0193d729fa4508a3394.zip |
Adding debian version 6.6.15-2.debian/6.6.15-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | debian/patches-rt/0004-drm-i915-Don-t-disable-interrupts-on-PREEMPT_RT-duri.patch | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/debian/patches-rt/0004-drm-i915-Don-t-disable-interrupts-on-PREEMPT_RT-duri.patch b/debian/patches-rt/0004-drm-i915-Don-t-disable-interrupts-on-PREEMPT_RT-duri.patch new file mode 100644 index 0000000000..9c386e5188 --- /dev/null +++ b/debian/patches-rt/0004-drm-i915-Don-t-disable-interrupts-on-PREEMPT_RT-duri.patch @@ -0,0 +1,85 @@ +From: Mike Galbraith <umgwanakikbuti@gmail.com> +Date: Sat, 27 Feb 2016 09:01:42 +0100 +Subject: [PATCH 04/10] drm/i915: Don't disable interrupts on PREEMPT_RT during + atomic updates +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +Commit + 8d7849db3eab7 ("drm/i915: Make sprite updates atomic") + +started disabling interrupts across atomic updates. This breaks on PREEMPT_RT +because within this section the code attempt to acquire spinlock_t locks which +are sleeping locks on PREEMPT_RT. + +According to the comment the interrupts are disabled to avoid random delays and +not required for protection or synchronisation. +If this needs to happen with disabled interrupts on PREEMPT_RT, and the +whole section is restricted to register access then all sleeping locks +need to be acquired before interrupts are disabled and some function +maybe moved after enabling interrupts again. +This includes: +- prepare_to_wait() + finish_wait() due its wake queue. +- drm_crtc_vblank_put() -> vblank_disable_fn() drm_device::vbl_lock. +- skl_pfit_enable(), intel_update_plane(), vlv_atomic_update_fifo() and + maybe others due to intel_uncore::lock +- drm_crtc_arm_vblank_event() due to drm_device::event_lock and + drm_device::vblank_time_lock. + +Don't disable interrupts on PREEMPT_RT during atomic updates. + +[bigeasy: drop local locks, commit message] + +Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/gpu/drm/i915/display/intel_crtc.c | 15 ++++++++++----- + 1 file changed, 10 insertions(+), 5 deletions(-) + +--- a/drivers/gpu/drm/i915/display/intel_crtc.c ++++ b/drivers/gpu/drm/i915/display/intel_crtc.c +@@ -534,7 +534,8 @@ void intel_pipe_update_start(struct inte + */ + intel_psr_wait_for_idle_locked(new_crtc_state); + +- local_irq_disable(); ++ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) ++ local_irq_disable(); + + crtc->debug.min_vbl = min; + crtc->debug.max_vbl = max; +@@ -559,11 +560,13 @@ void intel_pipe_update_start(struct inte + break; + } + +- local_irq_enable(); ++ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) ++ local_irq_enable(); + + timeout = schedule_timeout(timeout); + +- local_irq_disable(); ++ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) ++ local_irq_disable(); + } + + finish_wait(wq, &wait); +@@ -596,7 +599,8 @@ void intel_pipe_update_start(struct inte + return; + + irq_disable: +- local_irq_disable(); ++ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) ++ local_irq_disable(); + } + + #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE) +@@ -706,7 +710,8 @@ void intel_pipe_update_end(struct intel_ + intel_crtc_update_active_timings(new_crtc_state, + new_crtc_state->vrr.enable); + +- local_irq_enable(); ++ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) ++ local_irq_enable(); + + if (intel_vgpu_active(dev_priv)) + return; |