[RFC PATCH 1/1] drm/meson: Support drm_panic

Yao Zi
2024-10-01T21:07:54Z

This patch implements drm_plane_helper_funcs.get_scanout_buffer for
primary plane, enabling meson-drm to work with drm_panic.

This implementation tries to use current framebuffer as scanout buffer.
In case of AFBC enabled, we disable the decoder path and adjust OSD1
parameters in get_scanout_buffer to make the buffer linear.

Tested on TTY and Wayland session (Sway).

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
drivers/gpu/drm/meson/meson_plane.c | 47 +++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_plane.c b/drivers/gpu/drm/meson/meson_plane.c
index b43ac61201f3..b2def784c00d 100644
--- a/drivers/gpu/drm/meson/meson_plane.c
+++ b/drivers/gpu/drm/meson/meson_plane.c
@@ -20,6 +20,8 @@
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_panic.h>

#include "meson_plane.h"
#include "meson_registers.h"
@@ -419,10 +421,49 @@ static void meson_plane_atomic_disable(struct drm_plane *plane,
priv->viu.osd1_enabled = false;
}

+static int meson_plane_get_scanout_buffer(struct drm_plane *plane,
+ struct drm_scanout_buffer *sb)
+{
+ struct meson_plane *meson_plane = to_meson_plane(plane);
+ struct meson_drm *priv = meson_plane->priv;
+ struct drm_framebuffer *fb;
+
+ if (!meson_plane->enabled)
+ return -ENODEV;
+
+ if (priv->viu.osd1_afbcd) {
+ if (meson_vpu_is_compatible(priv, VPU_COMPATIBLE_GXM)) {
+ writel_relaxed(0, priv->io_base +
+ _REG(VIU_OSD1_BLK1_CFG_W4));
+ writel_relaxed(0, priv->io_base +
+ _REG(VIU_OSD1_BLK2_CFG_W4));
+ writel_bits_relaxed(OSD_ENDIANNESS_LE, OSD_ENDIANNESS_LE,
+ priv->io_base +
+ _REG(VIU_OSD1_BLK0_CFG_W0));
+ meson_viu_g12a_disable_osd1_afbc(priv);
+ } else if (meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
+ writel_bits_relaxed(OSD_DPATH_MALI_AFBCD, 0,
+ priv->io_base +
+ _REG(VIU_OSD1_CTRL_STAT2));
+ meson_viu_gxm_disable_osd1_afbc(priv);
+ }
+ }
+
+ fb = plane->state->fb;
+ sb->format = fb->format;
+ sb->width = fb->width;
+ sb->height = fb->height;
+ sb->pitch[0] = fb->pitches[0];
+ drm_gem_fb_vmap(fb, sb->map, NULL);
+
+ return 0;
+}
+
static const struct drm_plane_helper_funcs meson_plane_helper_funcs = {
- .atomic_check = meson_plane_atomic_check,
- .atomic_disable = meson_plane_atomic_disable,
- .atomic_update = meson_plane_atomic_update,
+ .atomic_check = meson_plane_atomic_check,
+ .atomic_disable = meson_plane_atomic_disable,
+ .atomic_update = meson_plane_atomic_update,
+ .get_scanout_buffer = meson_plane_get_scanout_buffer,
};

static bool meson_plane_format_mod_supported(struct drm_plane *plane,
--
2.46.0