[PATCH v2 2/2] drm/rockchip: vop: fix irq disabled after vop driver probed

[Heiko Stuebner]

From: Sandy Huang <hjc at rock-chips.com>

The vop irq is shared between vop and iommu and irq probing in the
iommu driver moved to the probe function recently. This can in some
cases lead to a stall if the irq is triggered while the vop driver
still has it disabled, but the vop irq handler gets called.

But there is no real need to disable the irq, as the vop can simply
also track its enabled state and ignore irqs in that case.
For this we can simply check the power-domain state of the vop,
similar to how the iommu driver does it.

So remove the enable/disable handling and add appropriate condition
to the irq handler.

changes in v2:
- move to just check the power-domain state
- add clock handling

Signed-off-by: Sandy Huang <hjc at rock-chips.com>
[add commit message, moved to pm_runtime_get_if_in_use]
Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 28 ++++++++++++++-------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index b55156b8ba3b..615a5b44bfe9 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -573,8 +573,6 @@ static int vop_enable(struct drm_crtc *crtc)
 
 	spin_unlock(&vop->reg_lock);
 
-	enable_irq(vop->irq);
-
 	drm_crtc_vblank_on(crtc);
 
 	return 0;
@@ -618,8 +616,6 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
 
 	vop_dsp_hold_valid_irq_disable(vop);
 
-	disable_irq(vop->irq);
-
 	vop->is_enabled = false;
 
 	/*
@@ -1195,6 +1191,16 @@ static irqreturn_t vop_isr(int irq, void *data)
 	uint32_t active_irqs;
 	int ret = IRQ_NONE;
 
+	/*
+	 * The irq is shared with the iommu. If the power-domain is off
+	 * the irq has to be targetted at the iommu.
+	 */
+	if (!pm_runtime_get_if_in_use(vop->dev))
+		return IRQ_NONE;
+
+	if (WARN_ON(vop_core_clks_enable(vop)))
+		goto out;
+
 	/*
 	 * interrupt register has interrupt status, enable and clear bits, we
 	 * must hold irq_lock to avoid a race with enable/disable_vblank().
@@ -1209,8 +1215,11 @@ static irqreturn_t vop_isr(int irq, void *data)
 	spin_unlock(&vop->irq_lock);
 
 	/* This is expected for vop iommu irqs, since the irq is shared */
-	if (!active_irqs)
-		return IRQ_NONE;
+	if (!active_irqs) {
+		ret = IRQ_NONE;
+		vop_core_clks_disable(vop);
+		goto out;
+	}
 
 	if (active_irqs & DSP_HOLD_VALID_INTR) {
 		complete(&vop->dsp_hold_completion);
@@ -1236,6 +1245,10 @@ static irqreturn_t vop_isr(int irq, void *data)
 		DRM_DEV_ERROR(vop->dev, "Unknown VOP IRQs: %#02x\n",
 			      active_irqs);
 
+	vop_core_clks_disable(vop);
+
+out:
+	pm_runtime_put(vop->dev);
 	return ret;
 }
 
@@ -1614,9 +1627,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data)
 	if (ret)
 		goto err_disable_pm_runtime;
 
-	/* IRQ is initially disabled; it gets enabled in power_on */
-	disable_irq(vop->irq);
-
 	return 0;
 
 err_disable_pm_runtime:
-- 
2.17.0