[PATCH 10/40] drm/rockchip: add mutex vop lock

[Thierry Escande]

From: zain wang <w...@rock-chips.com>

Add a lock to vop to avoid disabling the crtc while waiting for a line
flag while enabling psr. If we disable in the middle of waiting for the
line flag, we'll end up timing out or worse.

Signed-off-by: zain wang <w...@rock-chips.com>
Signed-off-by: Sean Paul <seanp...@chromium.org>
Signed-off-by: Thierry Escande <thierry.esca...@collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 30 +++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c 
b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 31304434847a..bf4b1a2f3fa4 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -117,6 +117,8 @@ struct vop {
        spinlock_t reg_lock;
        /* lock vop irq reg */
        spinlock_t irq_lock;
+       /* protects crtc enable/disable */
+       struct mutex vop_lock;
 
        unsigned int irq;
 
@@ -577,6 +579,7 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
 
        WARN_ON(vop->event);
 
+       mutex_lock(&vop->vop_lock);
        drm_crtc_vblank_off(crtc);
 
        /*
@@ -612,6 +615,7 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
        clk_disable(vop->aclk);
        clk_disable(vop->hclk);
        pm_runtime_put(vop->dev);
+       mutex_unlock(&vop->vop_lock);
 
        if (crtc->state->event && !crtc->state->active) {
                spin_lock_irq(&crtc->dev->event_lock);
@@ -882,10 +886,13 @@ static void vop_crtc_atomic_enable(struct drm_crtc *crtc,
        uint32_t pin_pol, val;
        int ret;
 
+       mutex_lock(&vop->vop_lock);
+
        WARN_ON(vop->event);
 
        ret = vop_enable(crtc);
        if (ret) {
+               mutex_unlock(&vop->vop_lock);
                DRM_DEV_ERROR(vop->dev, "Failed to enable vop (%d)\n", ret);
                return;
        }
@@ -949,6 +956,7 @@ static void vop_crtc_atomic_enable(struct drm_crtc *crtc,
        clk_set_rate(vop->dclk, adjusted_mode->clock * 1000);
 
        VOP_REG_SET(vop, common, standby, 0);
+       mutex_unlock(&vop->vop_lock);
 }
 
 static bool vop_fs_irq_is_pending(struct vop *vop)
@@ -1487,15 +1495,21 @@ int rockchip_drm_wait_vact_end(struct drm_crtc *crtc, 
unsigned int mstimeout)
 {
        struct vop *vop = to_vop(crtc);
        unsigned long jiffies_left;
+       int ret = 0;
 
        if (!crtc || !vop->is_enabled)
                return -ENODEV;
 
-       if (mstimeout <= 0)
-               return -EINVAL;
+       mutex_lock(&vop->vop_lock);
+       if (mstimeout <= 0) {
+               ret = -EINVAL;
+               goto out;
+       }
 
-       if (vop_line_flag_irq_is_enabled(vop))
-               return -EBUSY;
+       if (vop_line_flag_irq_is_enabled(vop)) {
+               ret = -EBUSY;
+               goto out;
+       }
 
        reinit_completion(&vop->line_flag_completion);
        vop_line_flag_irq_enable(vop);
@@ -1506,10 +1520,13 @@ int rockchip_drm_wait_vact_end(struct drm_crtc *crtc, 
unsigned int mstimeout)
 
        if (jiffies_left == 0) {
                DRM_DEV_ERROR(vop->dev, "Timeout waiting for IRQ\n");
-               return -ETIMEDOUT;
+               ret = -ETIMEDOUT;
+               goto out;
        }
 
-       return 0;
+out:
+       mutex_unlock(&vop->vop_lock);
+       return ret;
 }
 EXPORT_SYMBOL(rockchip_drm_wait_vact_end);
 
@@ -1559,6 +1576,7 @@ static int vop_bind(struct device *dev, struct device 
*master, void *data)
 
        spin_lock_init(&vop->reg_lock);
        spin_lock_init(&vop->irq_lock);
+       mutex_init(&vop->vop_lock);
 
        ret = devm_request_irq(dev, vop->irq, vop_isr,
                               IRQF_SHARED, dev_name(dev), vop);
-- 
2.14.1

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