Skip to content

drm/vc4: Skip input lines when doing a large downscale #7195

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
6by9 wants to merge 1 commit into
base: rpi-6.12.y
Choose a base branch
from
Draft

drm/vc4: Skip input lines when doing a large downscale #7195

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions drivers/gpu/drm/vc4/vc4_drv.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -480,6 +480,11 @@ struct vc4_plane_state {
*/
bool is_yuv444_unity;

/* Skip lines on large downscales to avoid consuming too much SDRAM
* bandwidth
*/
unsigned int vdownsample;

/* Our allocation in LBM for temporary storage during scaling. */
unsigned int lbm_handle;

Expand Down
39 changes: 32 additions & 7 deletions drivers/gpu/drm/vc4/vc4_plane.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -935,7 +935,7 @@ static void vc4_write_scaling_parameters(struct drm_plane_state *state,

/* Ch0 V-TPZ Words 0-2: Scaling Parameters, Recip, Context */
if (vc4_state->y_scaling[channel] == VC4_SCALING_TPZ) {
vc4_write_tpz(vc4_state, vc4_state->src_h[channel],
vc4_write_tpz(vc4_state, vc4_state->src_h[channel] / vc4_state->vdownsample,
vc4_state->crtc_h);
vc4_dlist_write(vc4_state, 0xc0c0c0c0);
}
Expand Down Expand Up @@ -1361,6 +1361,17 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
return 0;
}

if (vc4_state->y_scaling[0] == VC4_SCALING_TPZ &&
vc4_state->src_h[0] / vc4_state->crtc_h > 3) {
/* Downscaling by more than x3. Reduce the number of lines read
* to avoid exceeding SDRAM bandwidth.
*/
vc4_state->vdownsample = ((vc4_state->src_h[0] /
(vc4_state->crtc_h * 3)) >> 16) + 1;
} else {
vc4_state->vdownsample = 1;
}

width = vc4_state->src_w[0] >> 16;
height = vc4_state->src_h[0] >> 16;

Expand Down Expand Up @@ -1635,7 +1646,8 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
(mix_plane_alpha ? SCALER_POS2_ALPHA_MIX : 0) |
vc4_hvs4_get_alpha_blend_mode(state) |
VC4_SET_FIELD(width, SCALER_POS2_WIDTH) |
VC4_SET_FIELD(height, SCALER_POS2_HEIGHT));
VC4_SET_FIELD(height / vc4_state->vdownsample,
SCALER_POS2_HEIGHT));

/* Position Word 3: Context. Written by the HVS. */
vc4_dlist_write(vc4_state, 0xc0c0c0c0);
Expand Down Expand Up @@ -1689,7 +1701,8 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
vc4_state->pos2_offset = vc4_state->dlist_count;
vc4_dlist_write(vc4_state,
VC4_SET_FIELD(width, SCALER5_POS2_WIDTH) |
VC4_SET_FIELD(height, SCALER5_POS2_HEIGHT));
VC4_SET_FIELD(height / vc4_state->vdownsample,
SCALER5_POS2_HEIGHT));

/* Position Word 3: Context. Written by the HVS. */
vc4_dlist_write(vc4_state, 0xc0c0c0c0);
Expand All @@ -1713,14 +1726,15 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
vc4_dlist_write(vc4_state, 0xc0c0c0c0);

/* Pitch word 0 */
vc4_dlist_write(vc4_state, pitch[0]);
vc4_dlist_write(vc4_state, pitch[0] / vc4_state->vdownsample);

/* Pitch word 1/2 */
for (i = 1; i < num_planes; i++) {
if (hvs_format != HVS_PIXEL_FORMAT_H264 &&
hvs_format != HVS_PIXEL_FORMAT_YCBCR_10BIT) {
vc4_dlist_write(vc4_state,
VC4_SET_FIELD(fb->pitches[i],
VC4_SET_FIELD(fb->pitches[i] /
vc4_state->vdownsample,
SCALER_SRC_PITCH));
} else {
vc4_dlist_write(vc4_state, pitch[1]);
Expand Down Expand Up @@ -1938,6 +1952,17 @@ static int vc6_plane_mode_set(struct drm_plane *plane,
width = vc4_state->src_w[0] >> 16;
height = vc4_state->src_h[0] >> 16;

if (vc4_state->y_scaling[0] == VC4_SCALING_TPZ &&
vc4_state->src_h[0] / vc4_state->crtc_h > 3) {
/* Downscaling by more than x3. Reduce the number of lines read
* to avoid exceeding SDRAM bandwidth.
*/
vc4_state->vdownsample = ((vc4_state->src_h[0] /
(vc4_state->crtc_h * 3)) >> 16) + 1;
} else {
vc4_state->vdownsample = 1;
}

/* SCL1 is used for Cb/Cr scaling of planar formats. For RGB
* and 4:4:4, scl1 should be set to scl0 so both channels of
* the scaler do the same thing. For YUV, the Y plane needs
Expand Down Expand Up @@ -2152,7 +2177,7 @@ static int vc6_plane_mode_set(struct drm_plane *plane,
/* Position Word 2: Source Image Size */
vc4_state->pos2_offset = vc4_state->dlist_count;
vc4_dlist_write(vc4_state,
VC4_SET_FIELD(height - 1,
VC4_SET_FIELD((height / vc4_state->vdownsample) - 1,
SCALER6_POS2_SRC_LINES) |
VC4_SET_FIELD(width - 1,
SCALER6_POS2_SRC_WIDTH));
Expand Down Expand Up @@ -2187,7 +2212,7 @@ static int vc6_plane_mode_set(struct drm_plane *plane,
if (base_format_mod != DRM_FORMAT_MOD_BROADCOM_SAND128 &&
base_format_mod != DRM_FORMAT_MOD_BROADCOM_SAND256) {
vc4_dlist_write(vc4_state,
VC4_SET_FIELD(fb->pitches[i],
VC4_SET_FIELD((fb->pitches[i] * vc4_state->vdownsample),
SCALER6_PTR2_PITCH));
} else {
vc4_dlist_write(vc4_state, pitch[i]);
Expand Down