From: Kalyan Thota kalyant@codeaurora.org

Set the flag vblank_disable_immediate = true to turn off vblank irqs immediately as soon as drm_vblank_put is requested so that there are no irqs triggered during idle state. This will reduce cpu wakeups and help in power saving.

To enable vblank_disable_immediate flag the underlying KMS driver needs to support high precision vblank timestamping and also a reliable way of providing vblank counter which is incrementing at the leading edge of vblank.

This patch also brings in changes to support vblank_disable_immediate requirement in dpu driver.

Changes in v1: - Specify reason to add vblank timestamp support. (Rob Clark) - Add changes to provide vblank counter from dpu driver.

Changes in v2: - Fix warn stack reported by Rob Clark with v2 patch

Signed-off-by: Kalyan Thota kalyan_t@codeaurora.org --- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 80 +++++++++++++++++++++++++++++ drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 28 +++++++++- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 11 ++++ drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 5 ++ 4 files changed, 123 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index d4662e8..9a80981 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -65,6 +65,83 @@ static void dpu_crtc_destroy(struct drm_crtc *crtc) kfree(dpu_crtc); }

+static struct drm_encoder *get_encoder_from_crtc(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + struct drm_encoder *encoder; + + drm_for_each_encoder(encoder, dev) + if (encoder->crtc == crtc) + return encoder; + + return NULL; +} + +static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc) +{ + struct drm_encoder *encoder; + + encoder = get_encoder_from_crtc(crtc); + if (!encoder) { + DRM_ERROR("no encoder found for crtc %d\n", crtc->index); + return false; + } + + return dpu_encoder_get_frame_count(encoder); +} + +static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc, + bool in_vblank_irq, + int *vpos, int *hpos, + ktime_t *stime, ktime_t *etime, + const struct drm_display_mode *mode) +{ + unsigned int pipe = crtc->index; + struct drm_encoder *encoder; + int line, vsw, vbp, vactive_start, vactive_end, vfp_end; + + encoder = get_encoder_from_crtc(crtc); + if (!encoder) { + DRM_ERROR("no encoder found for crtc %d\n", pipe); + return false; + } + + vsw = mode->crtc_vsync_end - mode->crtc_vsync_start; + vbp = mode->crtc_vtotal - mode->crtc_vsync_end; + + /* + * the line counter is 1 at the start of the VSYNC pulse and VTOTAL at + * the end of VFP. Translate the porch values relative to the line + * counter positions. + */ + + vactive_start = vsw + vbp + 1; + vactive_end = vactive_start + mode->crtc_vdisplay; + + /* last scan line before VSYNC */ + vfp_end = mode->crtc_vtotal; + + if (stime) + *stime = ktime_get(); + + line = dpu_encoder_get_linecount(encoder); + + if (line < vactive_start) + line -= vactive_start; + else if (line > vactive_end) + line = line - vfp_end - vactive_start; + else + line -= vactive_start; + + *vpos = line; + *hpos = 0; + + if (etime) + *etime = ktime_get(); + + return true; +} + static void _dpu_crtc_setup_blend_cfg(struct dpu_crtc_mixer *mixer, struct dpu_plane_state *pstate, struct dpu_format *format) { @@ -1243,6 +1320,8 @@ static const struct drm_crtc_funcs dpu_crtc_funcs = { .early_unregister = dpu_crtc_early_unregister, .enable_vblank = msm_crtc_enable_vblank, .disable_vblank = msm_crtc_disable_vblank, + .get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp, + .get_vblank_counter = dpu_crtc_get_vblank_counter, };

static const struct drm_crtc_helper_funcs dpu_crtc_helper_funcs = { @@ -1251,6 +1330,7 @@ static const struct drm_crtc_helper_funcs dpu_crtc_helper_funcs = { .atomic_check = dpu_crtc_atomic_check, .atomic_begin = dpu_crtc_atomic_begin, .atomic_flush = dpu_crtc_atomic_flush, + .get_scanout_position = dpu_crtc_get_scanout_position, };

/* initialize crtc */ diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index f7f5c25..fb6546c 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -425,6 +425,32 @@ int dpu_encoder_helper_unregister_irq(struct dpu_encoder_phys *phys_enc, return 0; }

+int dpu_encoder_get_frame_count(struct drm_encoder *drm_enc) +{ + struct dpu_encoder_virt *dpu_enc; + struct dpu_encoder_phys *phy_enc; + + dpu_enc = to_dpu_encoder_virt(drm_enc); + phy_enc = dpu_enc ? dpu_enc->cur_master : NULL; + + return phy_enc ? atomic_read(&phy_enc->vsync_cnt) : 0; +} + +int dpu_encoder_get_linecount(struct drm_encoder *drm_enc) +{ + struct dpu_encoder_virt *dpu_enc; + struct dpu_encoder_phys *phys; + int linecount = 0; + + dpu_enc = to_dpu_encoder_virt(drm_enc); + phys = dpu_enc ? dpu_enc->cur_master : NULL; + + if (phys && phys->ops.get_line_count) + linecount = phys->ops.get_line_count(phys); + + return linecount; +} + void dpu_encoder_get_hw_resources(struct drm_encoder *drm_enc, struct dpu_encoder_hw_resources *hw_res) { @@ -1296,12 +1322,12 @@ static void dpu_encoder_vblank_callback(struct drm_encoder *drm_enc, DPU_ATRACE_BEGIN("encoder_vblank_callback"); dpu_enc = to_dpu_encoder_virt(drm_enc);

+ atomic_inc(&phy_enc->vsync_cnt); spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags); if (dpu_enc->crtc) dpu_crtc_vblank_callback(dpu_enc->crtc); spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);

- atomic_inc(&phy_enc->vsync_cnt); DPU_ATRACE_END("encoder_vblank_callback"); }

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h index b491346..99a5d73 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h @@ -156,5 +156,16 @@ void dpu_encoder_prepare_commit(struct drm_encoder *drm_enc); */ void dpu_encoder_set_idle_timeout(struct drm_encoder *drm_enc, u32 idle_timeout); +/** + * dpu_encoder_get_linecount - get interface line count for the encoder. + * @drm_enc: Pointer to previously created drm encoder structure + */ +int dpu_encoder_get_linecount(struct drm_encoder *drm_enc); + +/** + * dpu_encoder_get_frame_count - get interface frame count for the encoder. + * @drm_enc: Pointer to previously created drm encoder structure + */ +int dpu_encoder_get_frame_count(struct drm_encoder *drm_enc);

#endif /* __DPU_ENCODER_H__ */ diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c index 374b0e8..ed636f1 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c @@ -14,6 +14,7 @@

#include <drm/drm_crtc.h> #include <drm/drm_file.h> +#include <drm/drm_vblank.h>

#include "msm_drv.h" #include "msm_mmu.h" @@ -1020,6 +1021,10 @@ static int dpu_kms_hw_init(struct msm_kms *kms) */ dev->mode_config.allow_fb_modifiers = true;

+ dev->max_vblank_count = 0xffffffff; + /* Disable vblank irqs aggressively for power-saving */ + dev->vblank_disable_immediate = true; + /* * _dpu_kms_drm_obj_init should create the DRM related objects * i.e. CRTCs, planes, encoders, connectors and so forth