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>

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 04b619a8d064c8e77d05e8de994b3e3a0c0c5e4f..d041921b3bb9b1f0fd67acf4f8ac43860542b6c3 100644 (file)
--- 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);