samsung-sm8650/android_kernel_samsung_sm8650-modules
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disp: msm: sde: fix physical encoder spinlock usage

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While same spinlock can be used to protect a critical section
in both irq-handler and in non-irq context, in non-irq context
it is mandatory to use irqsave version of locking api to disable
irqs locally on the particular cpu. Otherwise, this could lead
to a deadlock if a non-irq thread holding the spinlock and irq
handler is scheduled on same cpu.

This change replaces physical encoder spinlock locking with
irqsave version of locking api in the non-irq context.

Change-Id: If73b4c995b75e9499d79fbe969d426427fd3a9d1
Signed-off-by: Prabhanjan Kandula <quic_pkandula@quicinc.com>
This commit is contained in:
Prabhanjan Kandula
2023-02-21 04:26:45 -08:00
committed by Gerrit - the friendly Code Review server
parent ace293849c
commit 1fdd965d0b
1 changed files with 6 additions and 4 deletions
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10
msm/sde/sde_encoder_phys_cmd.c
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@@ -213,6 +213,7 @@ void sde_encoder_restore_tearcheck_rd_ptr(struct sde_encoder_phys *phys_enc)
ktime_t nominal_period_ns, nominal_line_time_ns, panel_scan_line_ts_ns = 0;
ktime_t qsync_period_ns, time_into_frame_ns;
u32 qsync_timeout_lines, latency_margin_lines = 0, restored_rd_ptr_lines;
unsigned long flags;
u16 panel_scan_line;
int rc;
@@ -249,7 +250,7 @@ void sde_encoder_restore_tearcheck_rd_ptr(struct sde_encoder_phys *phys_enc)
}
/* Compensate the latency from DCS scan line response*/
spin_lock(phys_enc->enc_spinlock);
spin_lock_irqsave(phys_enc->enc_spinlock, flags);
sde_encoder_helper_get_pp_line_count(phys_enc->parent, info);
time_into_frame_ns = ktime_sub(ktime_get(), phys_enc->last_vsync_timestamp);
@@ -263,7 +264,7 @@ void sde_encoder_restore_tearcheck_rd_ptr(struct sde_encoder_phys *phys_enc)
if (hw_intf && hw_intf->ops.override_tear_rd_ptr_val)
hw_intf->ops.override_tear_rd_ptr_val(hw_intf, restored_rd_ptr_lines);
spin_unlock(phys_enc->enc_spinlock);
spin_unlock_irqrestore(phys_enc->enc_spinlock, flags);
SDE_EVT32(DRMID(phys_enc->parent), drm_mode_vrefresh(mode),
sde_enc->mode_info.qsync_min_fps,
@@ -282,6 +283,7 @@ static void _sde_encoder_phys_cmd_setup_sim_qsync_frame(struct sde_encoder_phys
struct sde_encoder_virt *sde_enc;
struct sde_connector *sde_conn;
struct drm_connector *conn;
unsigned long flags;
u32 qsync_min_fps = 0, nominal_fps = 0, frame_rate = 0;
u32 nominal_period_us, qsync_min_period_us, time_since_vsync_us;
int time_before_nominal_vsync_us, time_before_timeout_vsync_us;
@@ -301,7 +303,7 @@ static void _sde_encoder_phys_cmd_setup_sim_qsync_frame(struct sde_encoder_phys
return;
}
spin_lock(phys_enc->enc_spinlock);
spin_lock_irqsave(phys_enc->enc_spinlock, flags);
switch (frame) {
case SDE_SIM_QSYNC_FRAME_NOMINAL:
frame_rate = nominal_fps;
@@ -358,7 +360,7 @@ static void _sde_encoder_phys_cmd_setup_sim_qsync_frame(struct sde_encoder_phys
phys_enc->hw_intf->ops.vsync_sel(phys_enc->hw_intf, SDE_VSYNC_SOURCE_WD_TIMER_0);
phys_enc->ops.control_te(phys_enc, true);
phys_enc->sim_qsync_frame = frame;
spin_unlock(phys_enc->enc_spinlock);
spin_unlock_irqrestore(phys_enc->enc_spinlock, flags);
}
static void _sde_encoder_phys_cmd_process_sim_qsync_event(struct sde_encoder_phys *phys_enc,