Re: [PATCH] drm/rockchip: vop: power off until vop standby take effect

On 2015年02月02日 10:07, Daniel Kurtz wrote:

Hi Mark, Heiko,

On Sat, Jan 31, 2015 at 4:41 PM, Mark Yao mark.yao@rock-chips.com wrote:

...

Vop standby will take effect 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.

Signed-off-by: Mark Yao mark.yao@rock-chips.com

drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 76 ++++++++++++++++++++++----- 1 file changed, 63 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index fb25836..47ea61f 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 +383,34 @@ static bool is_alpha_support(uint32_t format) } }

+static void vop_dsp_hold_valid_irq_enable(struct vop *vop) +{

•   unsigned long flags;
  

•   BUG_ON(!vop->is_enabled);
  

Re: Heiko "use a WARN_ON":

If the VOP clock is off, then the system will just hang when trying to write the VOP register so in this case, BUG_ON gives a more reliable crash dump than the hang.

In this way, you are right, if vop clocks is disabled, write vop register will hang system, and the WARN_ON crash dump may be have no chance to print.

...

•   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;
  

•   BUG_ON(!vop->is_enabled);
  

•   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 +483,36 @@ 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 until end of current frame,
  

"Vop standby will take effect at end of current frame"

OK

...

•    * 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 +1125,7 @@ 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 +1144,24 @@ 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) {
  

•           if (!completion_done(&vop->dsp_hold_completion))
  

Why is this "completion_done" check needed? I guess it doesn't help, but isn't strictly needed, since the dsp_hold_completion is a one shot, right?

Right, the DSP_HOLD_VALID_INTR only happen when standby complete, one standby one irq.

Mark

In any case, this should work as it is, so:

Reviewed-by: Daniel Kurtz djkurtz@chromium.org

...

•                   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 +1243,7 @@ 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);
  

-- 1.7.9.5