drm/rockchip: vop: power off until vop standby take effect

Vop standby will take effect at end of current frame,
if dsp_hold_valid_irq happen, it means vop standby complete.

we must wait standby complete when we want to disable aclk,
if not, memory bus maybe dead.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

1 files changed, 64 insertions, 13 deletions

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 04b619a8d064..d041921b3bb9 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -89,6 +89,7 @@ struct vop {
         /* mutex vsync_ work */
         struct mutex vsync_mutex;
         bool vsync_work_pending;
+        struct completion dsp_hold_completion;
 
         const struct vop_data *data;
 
@@ -382,6 +383,36 @@ static bool is_alpha_support(uint32_t format)
         }
 }
 
+static void vop_dsp_hold_valid_irq_enable(struct vop *vop)
+{
+        unsigned long flags;
+
+        if (WARN_ON(!vop->is_enabled))
+                return;
+
+        spin_lock_irqsave(&vop->irq_lock, flags);
+
+        vop_mask_write(vop, INTR_CTRL0, DSP_HOLD_VALID_INTR_MASK,
+                       DSP_HOLD_VALID_INTR_EN(1));
+
+        spin_unlock_irqrestore(&vop->irq_lock, flags);
+}
+
+static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
+{
+        unsigned long flags;
+
+        if (WARN_ON(!vop->is_enabled))
+                return;
+
+        spin_lock_irqsave(&vop->irq_lock, flags);
+
+        vop_mask_write(vop, INTR_CTRL0, DSP_HOLD_VALID_INTR_MASK,
+                       DSP_HOLD_VALID_INTR_EN(0));
+
+        spin_unlock_irqrestore(&vop->irq_lock, flags);
+}
+
 static void vop_enable(struct drm_crtc *crtc)
 {
         struct vop *vop = to_vop(crtc);
@@ -454,26 +485,36 @@ static void vop_disable(struct drm_crtc *crtc)
 
         drm_vblank_off(crtc->dev, vop->pipe);
 
-        disable_irq(vop->irq);
-
         /*
-         * TODO: Since standby doesn't take effect until the next vblank,
-         * when we turn off dclk below, the vop is probably still active.
+         * Vop standby will take effect at end of current frame,
+         * if dsp hold valid irq happen, it means standby complete.
+         *
+         * we must wait standby complete when we want to disable aclk,
+         * if not, memory bus maybe dead.
          */
+        reinit_completion(&vop->dsp_hold_completion);
+        vop_dsp_hold_valid_irq_enable(vop);
+
         spin_lock(&vop->reg_lock);
 
         VOP_CTRL_SET(vop, standby, 1);
 
         spin_unlock(&vop->reg_lock);
 
+        wait_for_completion(&vop->dsp_hold_completion);
+
+        vop_dsp_hold_valid_irq_disable(vop);
+
+        disable_irq(vop->irq);
+
         vop->is_enabled = false;
+
         /*
-         * disable dclk to stop frame scan, so we can safely detach iommu,
+         * vop standby complete, so iommu detach is safe.
          */
-        clk_disable(vop->dclk);
-
         rockchip_drm_dma_detach_device(vop->drm_dev, vop->dev);
 
+        clk_disable(vop->dclk);
         clk_disable(vop->aclk);
         clk_disable(vop->hclk);
 }
@@ -1086,6 +1127,7 @@ static irqreturn_t vop_isr(int irq, void *data)
         struct vop *vop = data;
         uint32_t intr0_reg, active_irqs;
         unsigned long flags;
+        int ret = IRQ_NONE;
 
         /*
          * INTR_CTRL0 register has interrupt status, enable and clear bits, we
@@ -1104,15 +1146,23 @@ static irqreturn_t vop_isr(int irq, void *data)
         if (!active_irqs)
                 return IRQ_NONE;
 
-        /* Only Frame Start Interrupt is enabled; other irqs are spurious. */
-        if (!(active_irqs & FS_INTR)) {
-                DRM_ERROR("Unknown VOP IRQs: %#02x\n", active_irqs);
-                return IRQ_NONE;
+        if (active_irqs & DSP_HOLD_VALID_INTR) {
+                complete(&vop->dsp_hold_completion);
+                active_irqs &= ~DSP_HOLD_VALID_INTR;
+                ret = IRQ_HANDLED;
         }
 
-        drm_handle_vblank(vop->drm_dev, vop->pipe);
+        if (active_irqs & FS_INTR) {
+                drm_handle_vblank(vop->drm_dev, vop->pipe);
+                active_irqs &= ~FS_INTR;
+                ret = (vop->vsync_work_pending) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
+        }
 
-        return (vop->vsync_work_pending) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
+        /* Unhandled irqs are spurious. */
+        if (active_irqs)
+                DRM_ERROR("Unknown VOP IRQs: %#02x\n", active_irqs);
+
+        return ret;
 }
 
 static int vop_create_crtc(struct vop *vop)
@@ -1194,6 +1244,7 @@ static int vop_create_crtc(struct vop *vop)
                 goto err_cleanup_crtc;
         }
 
+        init_completion(&vop->dsp_hold_completion);
         crtc->port = port;
         vop->pipe = drm_crtc_index(crtc);
         rockchip_register_crtc_funcs(drm_dev, &private_crtc_funcs, vop->pipe);