[PATCH v5 04/36] drm/rockchip: add mutex vop lock

Enric Balletbo i Serra
2018-03-09T22:22:55Z

From: zain wang <wzz@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 <wzz@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.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 158e79e5062e..b601c59e76a8 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;

@@ -569,6 +571,7 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,

WARN_ON(vop->event);

+ mutex_lock(&vop->vop_lock);
drm_crtc_vblank_off(crtc);

/*
@@ -604,6 +607,7 @@ 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);
@@ -868,10 +872,13 @@ 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;
}
@@ -935,6 +942,7 @@ 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)
@@ -1473,15 +1481,21 @@ 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);
@@ -1492,10 +1506,13 @@ 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);

@@ -1545,6 +1562,7 @@ 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);
--
2.16.1