-----Original Message-----
From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Sent: Tuesday, January 31, 2023 6:29 PM
To: Vinod Polimera (QUIC) <quic_vpolimer@xxxxxxxxxxx>; dri-
devel@xxxxxxxxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx;
freedreno@xxxxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx; robdclark@xxxxxxxxx;
dianders@xxxxxxxxxxxx; swboyd@xxxxxxxxxxxx; Kalyan Thota (QUIC)
<quic_kalyant@xxxxxxxxxxx>; Kuogee Hsieh (QUIC)
<quic_khsieh@xxxxxxxxxxx>; Vishnuvardhan Prodduturi (QUIC)
<quic_vproddut@xxxxxxxxxxx>; Bjorn Andersson (QUIC)
<quic_bjorande@xxxxxxxxxxx>; Abhinav Kumar (QUIC)
<quic_abhinavk@xxxxxxxxxxx>; Sankeerth Billakanti (QUIC)
<quic_sbillaka@xxxxxxxxxxx>
Subject: Re: [PATCH v12 13/14] drm/msm/disp/dpu: add PSR support for eDP
interface in dpu driver
On 30/01/2023 17:11, Vinod Polimera wrote:
Enable PSR on eDP interface using drm self-refresh librabry.
This patch uses a trigger from self-refresh library to enter/exit
into PSR, when there are no updates from framework.
Signed-off-by: Kalyan Thota <quic_kalyant@xxxxxxxxxxx>
Signed-off-by: Vinod Polimera <quic_vpolimer@xxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 13 ++++++++++++-
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 14 ++++++++++++++
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 2 +-
3 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index f29a339..60e5984 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -21,6 +21,7 @@
#include <drm/drm_probe_helper.h>
#include <drm/drm_rect.h>
#include <drm/drm_vblank.h>
+#include <drm/drm_self_refresh_helper.h>
#include "dpu_kms.h"
#include "dpu_hw_lm.h"
@@ -1021,6 +1022,9 @@ static void dpu_crtc_disable(struct drm_crtc
*crtc,
DRM_DEBUG_KMS("crtc%d\n", crtc->base.id);
+ if (old_crtc_state->self_refresh_active)
+ return;
+
I have been looking at the crtc_needs_disable(). It explicitly mentions
that 'We also need to run through the crtc_funcs->disable() function
[..] if it's transitioning to self refresh mode...'. Don't we need to
perform some cleanup here (like disabling the vblank irq handling,
freeing the bandwidth, etc)?
/* Disable/save vblank irq handling */
drm_crtc_vblank_off(crtc);
@@ -1577,7 +1581,7 @@ struct drm_crtc *dpu_crtc_init(struct drm_device
*dev, struct drm_plane *plane,
{
struct drm_crtc *crtc = NULL;
struct dpu_crtc *dpu_crtc = NULL;
- int i;
+ int i, ret;
dpu_crtc = kzalloc(sizeof(*dpu_crtc), GFP_KERNEL);
if (!dpu_crtc)
@@ -1614,6 +1618,13 @@ struct drm_crtc *dpu_crtc_init(struct
drm_device *dev, struct drm_plane *plane,
/* initialize event handling */
spin_lock_init(&dpu_crtc->event_lock);
+ ret = drm_self_refresh_helper_init(crtc);
+ if (ret) {
+ DPU_ERROR("Failed to initialize %s with self-refresh
helpers %d\n",
+ crtc->name, ret);
+ return ERR_PTR(ret);
+ }
+
DRM_DEBUG_KMS("%s: successfully initialized crtc\n", dpu_crtc-
name);
return crtc;
}
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 01b7509..450abb1 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -12,6 +12,7 @@
#include <linux/kthread.h>
#include <linux/seq_file.h>
+#include <drm/drm_atomic.h>
#include <drm/drm_crtc.h>
#include <drm/drm_file.h>
#include <drm/drm_probe_helper.h>
@@ -1212,11 +1213,24 @@ static void
dpu_encoder_virt_atomic_disable(struct drm_encoder *drm_enc,
struct drm_atomic_state *state)
{
struct dpu_encoder_virt *dpu_enc = NULL;
+ struct drm_crtc *crtc;
+ struct drm_crtc_state *old_state = NULL;
int i = 0;
dpu_enc = to_dpu_encoder_virt(drm_enc);
DPU_DEBUG_ENC(dpu_enc, "\n");
+ crtc = drm_atomic_get_old_crtc_for_encoder(state, drm_enc);
+ if (crtc)
+ old_state = drm_atomic_get_old_crtc_state(state, crtc);
+
+ /*
+ * The encoder is already disabled if self refresh mode was
set earlier,
+ * in the old_state for the corresponding crtc.
+ */
+ if (old_state && old_state->self_refresh_active)
+ return;
+
Again the same question here, doesn't crtc_needs_disable() take care of
this clause? I might be missing something in the PSR state transitions.
Could you please add some explanation here?
