Commit 6b44aa55 authored by Val Packett's avatar Val Packett Committed by Heiko Stuebner
Browse files

drm/rockchip: vop: clear DMA stop bit on RK3066 



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: f4a6de85 ("drm: rockchip: vop: add rk3066 vop definitions")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarVal Packett <val@packett.cool>
Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624204054.5524-2-val@packett.cool
parent ab03974d

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

+4 −0
Original line number Diff line number Diff line
@@ -1583,6 +1583,10 @@ 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);



	/*

drivers/gpu/drm/rockchip/rockchip_drm_vop.h

+1 −0
Original line number Diff line number Diff line
@@ -122,6 +122,7 @@ 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;

};

drivers/gpu/drm/rockchip/rockchip_vop_reg.c

+1 −0
Original line number Diff line number Diff line
@@ -466,6 +466,7 @@ 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),