This is a note to let you know that I've just added the patch titled
drm/rockchip: vop: clear DMA stop bit on RK3066
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-rockchip-vop-clear-dma-stop-bit-on-rk3066.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 324ce568ab1f5c1bb99642167faa30c8e6ea98b5
Author: Val Packett <val@xxxxxxxxxxxx>
Date: Mon Jun 24 17:40:48 2024 -0300
drm/rockchip: vop: clear DMA stop bit on RK3066
[ Upstream commit 6b44aa559d6c7f4ea591ef9d2352a7250138d62a ]
The RK3066 VOP sets a dma_stop bit when it's done scanning out a frame
and needs the driver to acknowledge that by clearing the bit.
Unless we clear it "between" frames, the RGB output only shows noise
instead of the picture. atomic_flush is the place for it that least
affects other code (doing it on vblank would require converting all
other usages of the reg_lock to spin_(un)lock_irq, which would affect
performance for everyone).
This seems to be a redundant synchronization mechanism that was removed
in later iterations of the VOP hardware block.
Fixes: f4a6de855eae ("drm: rockchip: vop: add rk3066 vop definitions")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Val Packett <val@xxxxxxxxxxxx>
Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624204054.5524-2-val@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 3d5e463757f55..40e733fd8862a 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1544,6 +1544,10 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
VOP_AFBC_SET(vop, enable, s->enable_afbc);
vop_cfg_done(vop);
+ /* Ack the DMA transfer of the previous frame (RK3066). */
+ if (VOP_HAS_REG(vop, common, dma_stop))
+ VOP_REG_SET(vop, common, dma_stop, 0);
+
spin_unlock(&vop->reg_lock);
/*
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index 14179e89bd215..32d1783be01d3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -103,6 +103,7 @@ struct vop_common {
struct vop_reg lut_buffer_index;
struct vop_reg gate_en;
struct vop_reg mmu_en;
+ struct vop_reg dma_stop;
struct vop_reg out_mode;
struct vop_reg standby;
};
diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
index de7eb2fda4833..3bcc3d614ee1d 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
@@ -424,6 +424,7 @@ static const struct vop_output rk3066_output = {
};
static const struct vop_common rk3066_common = {
+ .dma_stop = VOP_REG(RK3066_SYS_CTRL0, 0x1, 0),
.standby = VOP_REG(RK3066_SYS_CTRL0, 0x1, 1),
.out_mode = VOP_REG(RK3066_DSP_CTRL0, 0xf, 0),
.cfg_done = VOP_REG(RK3066_REG_CFG_DONE, 0x1, 0),
