[PATCH 3/3] drm/vc4: Use runtime PM to power cycle the device when the GPU hangs.
From: Eric Anholt
Date: Mon Feb 08 2016 - 19:20:31 EST
This gets us functional GPU reset again, like we had until a refactor
at merge time. Tested with a little patch to stuff in a broken binner
job every 100 frames.
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_drv.h | 6 +++++-
drivers/gpu/drm/vc4/vc4_gem.c | 26 +++++++++++++++++++++-----
drivers/gpu/drm/vc4/vc4_v3d.c | 12 ------------
3 files changed, 26 insertions(+), 18 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index b65e785..83db0b7 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -91,6 +91,11 @@ struct vc4_dev {
struct vc4_bo *overflow_mem;
struct work_struct overflow_mem_work;
+ int power_refcount;
+
+ /* Mutex controlling the power refcount. */
+ struct mutex power_lock;
+
struct {
struct timer_list timer;
struct work_struct reset_work;
@@ -449,7 +454,6 @@ void vc4_plane_async_set_fb(struct drm_plane *plane,
extern struct platform_driver vc4_v3d_driver;
int vc4_v3d_debugfs_ident(struct seq_file *m, void *unused);
int vc4_v3d_debugfs_regs(struct seq_file *m, void *unused);
-int vc4_v3d_set_power(struct vc4_dev *vc4, bool on);
/* vc4_validate.c */
int
diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index 440ad03..5df46d6 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -229,8 +229,16 @@ vc4_reset(struct drm_device *dev)
struct vc4_dev *vc4 = to_vc4_dev(dev);
DRM_INFO("Resetting GPU.\n");
- vc4_v3d_set_power(vc4, false);
- vc4_v3d_set_power(vc4, true);
+
+ mutex_lock(&vc4->power_lock);
+ if (vc4->power_refcount) {
+ /* Power the device off and back on the by dropping the
+ * reference on runtime PM.
+ */
+ pm_runtime_put_sync_suspend(&vc4->v3d->pdev->dev);
+ pm_runtime_get_sync(&vc4->v3d->pdev->dev);
+ }
+ mutex_unlock(&vc4->power_lock);
vc4_irq_reset(dev);
@@ -646,7 +654,10 @@ vc4_complete_exec(struct drm_device *dev, struct vc4_exec_info *exec)
}
mutex_unlock(&dev->struct_mutex);
- pm_runtime_put(&vc4->v3d->pdev->dev);
+ mutex_lock(&vc4->power_lock);
+ if (--vc4->power_refcount == 0)
+ pm_runtime_put(&vc4->v3d->pdev->dev);
+ mutex_unlock(&vc4->power_lock);
kfree(exec);
}
@@ -785,7 +796,7 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
struct vc4_dev *vc4 = to_vc4_dev(dev);
struct drm_vc4_submit_cl *args = data;
struct vc4_exec_info *exec;
- int ret;
+ int ret = 0;
if ((args->flags & ~VC4_SUBMIT_CL_USE_CLEAR_COLOR) != 0) {
DRM_ERROR("Unknown flags: 0x%02x\n", args->flags);
@@ -798,7 +809,10 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
return -ENOMEM;
}
- ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
+ mutex_lock(&vc4->power_lock);
+ if (vc4->power_refcount++ == 0)
+ ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
+ mutex_unlock(&vc4->power_lock);
if (ret < 0) {
kfree(exec);
return ret;
@@ -858,6 +872,8 @@ vc4_gem_init(struct drm_device *dev)
(unsigned long)dev);
INIT_WORK(&vc4->job_done_work, vc4_job_done_work);
+
+ mutex_init(&vc4->power_lock);
}
void
diff --git a/drivers/gpu/drm/vc4/vc4_v3d.c b/drivers/gpu/drm/vc4/vc4_v3d.c
index 930851f..7b11e21 100644
--- a/drivers/gpu/drm/vc4/vc4_v3d.c
+++ b/drivers/gpu/drm/vc4/vc4_v3d.c
@@ -145,18 +145,6 @@ int vc4_v3d_debugfs_ident(struct seq_file *m, void *unused)
}
#endif /* CONFIG_DEBUG_FS */
-int
-vc4_v3d_set_power(struct vc4_dev *vc4, bool on)
-{
- /* XXX: This interface is needed for GPU reset, and the way to
- * do it is to turn our power domain off and back on. We
- * can't just reset from within the driver, because the reset
- * bits are in the power domain's register area, and get set
- * during the poweron process.
- */
- return 0;
-}
-
static void vc4_v3d_init_hw(struct drm_device *dev)
{
struct vc4_dev *vc4 = to_vc4_dev(dev);
--
2.7.0