On 12/05/2022 10:52, Thomas Zimmermann wrote:
Hi
Am 11.05.22 um 17:28 schrieb Jocelyn Falempe:
Add support for atomic update of gamma lut.
With this patch the "Night light" feature of gnome3
is working properly on mgag200.
v2:
- Add a default linear gamma function
- renamed functions with mgag200 prefix
- use format's 4cc code instead of bit depth
- use better interpolation for 16bits gamma
- remove legacy function mga_crtc_load_lut()
- can't remove the call to drm_mode_crtc_set_gamma_size()
because it doesn't work with userspace.
- other small refactors
Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
I already gave a Tested-by on the first iteration. It's good practice to
add these tags in follow-up patches unless the patch has changed entirely.
Sorry, I though I changed too much code in v2 to add it.
A few more comments are below. With those fixed:
Reviewed-by: Thomas Zimmermann <tzimemrmann@xxxxxxx>
I suggest to post another version of the patch and merge it if no
further comments arrive within 2 days.
---
drivers/gpu/drm/mgag200/mgag200_mode.c | 125 ++++++++++++++++---------
1 file changed, 81 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c
b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 6e18d3bbd720..b748bc5b0e93 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -32,57 +32,76 @@
* This file contains setup code for the CRTC.
*/
-static void mga_crtc_load_lut(struct drm_crtc *crtc)
+static void mgag200_crtc_set_gamma_linear(struct mga_device *mdev,
+ uint32_t format)
{
- struct drm_device *dev = crtc->dev;
- struct mga_device *mdev = to_mga_device(dev);
- struct drm_framebuffer *fb;
- u16 *r_ptr, *g_ptr, *b_ptr;
int i;
- if (!crtc->enabled)
- return;
-
- if (!mdev->display_pipe.plane.state)
- return;
+ WREG8(DAC_INDEX + MGA1064_INDEX, 0);
- fb = mdev->display_pipe.plane.state->fb;
+ switch (format) {
+ case DRM_FORMAT_RGB565:
+ /* Use better interpolation, to take 32 values from 0 to 255 */
+ for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
+ }
+ /* Green has one more bit, so add padding with 0 for red and
blue. */
+ for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
+ }
+ break;
+ case DRM_FORMAT_RGB888:
+ case DRM_FORMAT_XRGB8888:
+ for (i = 0; i < MGAG200_LUT_SIZE; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
+ }
These loops look much nicer to me.
+ break;
+ default:
+ drm_warn_once(&mdev->base, "Unsupported format for gamma
%d\n", format);
There's a print format modifier for 4cc formats. It's %p4cc and expects
a pointer to the format's 4cc code. See 'git grep p4cc' for examples.
ok, that's a cool feature.
The comment itself is not easy to understand. Maybe "Unsupported format
%p4cc for gamma correction.\n" ?
Sure, having good error message is always helpful.
+ break;
+ }
+}
- r_ptr = crtc->gamma_store;
- g_ptr = r_ptr + crtc->gamma_size;
- b_ptr = g_ptr + crtc->gamma_size;
+static void mgag200_crtc_set_gamma(struct mga_device *mdev,
+ struct drm_color_lut *lut,
+ uint32_t format)
+{
+ int i;
WREG8(DAC_INDEX + MGA1064_INDEX, 0);
- if (fb && fb->format->cpp[0] * 8 == 16) {
- int inc = (fb->format->depth == 15) ? 8 : 4;
- u8 r, b;
- for (i = 0; i < MGAG200_LUT_SIZE; i += inc) {
- if (fb->format->depth == 16) {
- if (i > (MGAG200_LUT_SIZE >> 1)) {
- r = b = 0;
- } else {
- r = *r_ptr++ >> 8;
- b = *b_ptr++ >> 8;
- r_ptr++;
- b_ptr++;
- }
- } else {
- r = *r_ptr++ >> 8;
- b = *b_ptr++ >> 8;
- }
- /* VGA registers */
- WREG8(DAC_INDEX + MGA1064_COL_PAL, r);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, *g_ptr++ >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, b);
+ switch (format) {
+ case DRM_FORMAT_RGB565:
+ /* Use better interpolation, to take 32 values from lut[0] to
lut[255] */
+ for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].red
>> 8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i /
16].green >> 8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i /
4].blue >> 8);
}
- return;
- }
- for (i = 0; i < MGAG200_LUT_SIZE; i++) {
- /* VGA registers */
- WREG8(DAC_INDEX + MGA1064_COL_PAL, *r_ptr++ >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, *g_ptr++ >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, *b_ptr++ >> 8);
+ /* Green has one more bit, so add padding with 0 for red and
blue. */
+ for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i /
16].green >> 8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
+ }
+ break;
+ case DRM_FORMAT_RGB888:
+ case DRM_FORMAT_XRGB8888:
+ for (i = 0; i < MGAG200_LUT_SIZE; i++) {
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].red >> 8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].green >> 8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].blue >> 8);
+ }
+ break;
+ default:
+ drm_warn_once(&mdev->base, "Unsupported format for gamma
%d\n", format);
Same as above.
+ break;
}
}
@@ -900,7 +919,11 @@ mgag200_simple_display_pipe_enable(struct
drm_simple_display_pipe *pipe,
if (mdev->type == G200_WB || mdev->type == G200_EW3)
mgag200_g200wb_release_bmc(mdev);
- mga_crtc_load_lut(crtc);
+ if (crtc_state->gamma_lut)
+ mgag200_crtc_set_gamma(mdev, crtc_state->gamma_lut->data,
fb->format->format);
Nitpicking: I'd give the format before the LUT data. It's more logical
and aligns with '_set_gamma_linear'. I'd also pass fb->format instead of
fb->format->format.
ok, I will do that too.
+ else
+ mgag200_crtc_set_gamma_linear(mdev, fb->format->format);
+
mgag200_enable_display(mdev);
mgag200_handle_damage(mdev, fb, &fullscreen,
&shadow_plane_state->data[0]);
@@ -945,6 +968,14 @@ mgag200_simple_display_pipe_check(struct
drm_simple_display_pipe *pipe,
return ret;
}
+ if (crtc_state->color_mgmt_changed && crtc_state->gamma_lut) {
+ if (crtc_state->gamma_lut->length !=
+ MGAG200_LUT_SIZE * sizeof(struct drm_color_lut)) {
+ drm_err(dev, "Wrong size for gamma_lut %ld\n",
The kernel bot complained about '%ld'. I think %zu is the one for size_t.
I had no warnings when building on x86_64, but printf format is a bit
tricky to get right.
+ crtc_state->gamma_lut->length);
+ return -EINVAL;
+ }
+ }
return 0;
}
@@ -953,6 +984,7 @@ mgag200_simple_display_pipe_update(struct
drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane *plane = &pipe->plane;
+ struct drm_crtc *crtc = &pipe->crtc;
struct drm_device *dev = plane->dev;
struct mga_device *mdev = to_mga_device(dev);
struct drm_plane_state *state = plane->state;
@@ -963,6 +995,9 @@ mgag200_simple_display_pipe_update(struct
drm_simple_display_pipe *pipe,
if (!fb)
return;
+ if (crtc->state->color_mgmt_changed && crtc->state->gamma_lut)
+ mgag200_crtc_set_gamma(mdev, crtc->state->gamma_lut->data,
fb->format->format);
+
This also needs a call to _set_gamma_linear?
No, I think the gamma table should be properly initialized in
mgag200_simple_display_pipe_enable(), so only set it if userspace gives
a new table.
Best regards
Thomas
if (drm_atomic_helper_damage_merged(old_state, state, &damage))
mgag200_handle_damage(mdev, fb, &damage,
&shadow_plane_state->data[0]);
}
@@ -1107,9 +1142,11 @@ int mgag200_modeset_init(struct mga_device *mdev)
return ret;
}
- /* FIXME: legacy gamma tables; convert to CRTC state */
+ /* FIXME: legacy gamma tables, but atomic gamma doesn't work
without */
drm_mode_crtc_set_gamma_size(&pipe->crtc, MGAG200_LUT_SIZE);
+ drm_crtc_enable_color_mgmt(&pipe->crtc, 0, false, MGAG200_LUT_SIZE);
+
drm_mode_config_reset(dev);
return 0;
Thanks for your review, I will send a v3 soon,
--
Jocelyn
