We want to remove uses of do_gettimeofday() from the kernel since the
resulting timeval structure overflows in 2038. This is not a problem for
this particular use, but do_gettimeofday() is also not an appropriate
method for measuring time intervals, since it requires a conversion into
microseconds and is complicated to work with.
ktime_get() is a better replacement, as it works with the monontonic
kernel timebase and requires a minimum of computation.
I'm slightly changing the output from microseconds to nanoseconds here,
to avoid introducing a new division operation. This should be fine
since the value is only used for debugging.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/gpu/drm/via/via_drv.h | 4 ++--
drivers/gpu/drm/via/via_irq.c | 21 +++++++--------------
2 files changed, 9 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/via/via_drv.h b/drivers/gpu/drm/via/via_drv.h
index 9873942ca8f4..6d1ae834484c 100644
--- a/drivers/gpu/drm/via/via_drv.h
+++ b/drivers/gpu/drm/via/via_drv.h
@@ -74,9 +74,9 @@ typedef struct drm_via_private {
volatile uint32_t *last_pause_ptr;
volatile uint32_t *hw_addr_ptr;
drm_via_ring_buffer_t ring;
- struct timeval last_vblank;
+ ktime_t last_vblank;
int last_vblank_valid;
- unsigned usec_per_vblank;
+ ktime_t nsec_per_vblank;
atomic_t vbl_received;
drm_via_state_t hc_state;
char pci_buf[VIA_PCI_BUF_SIZE];
diff --git a/drivers/gpu/drm/via/via_irq.c b/drivers/gpu/drm/via/via_irq.c
index ea8172c747a2..24e71578af4d 100644
--- a/drivers/gpu/drm/via/via_irq.c
+++ b/drivers/gpu/drm/via/via_irq.c
@@ -88,13 +88,6 @@ static int via_num_unichrome = ARRAY_SIZE(via_unichrome_irqs);
static int via_irqmap_unichrome[] = {-1, -1, -1, 0, -1, 1};
-static unsigned time_diff(struct timeval *now, struct timeval *then)
-{
- return (now->tv_usec >= then->tv_usec) ?
- now->tv_usec - then->tv_usec :
- 1000000 - (then->tv_usec - now->tv_usec);
-}
-
u32 via_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
{
drm_via_private_t *dev_priv = dev->dev_private;
@@ -111,7 +104,7 @@ irqreturn_t via_driver_irq_handler(int irq, void *arg)
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
u32 status;
int handled = 0;
- struct timeval cur_vblank;
+ ktime_t cur_vblank;
drm_via_irq_t *cur_irq = dev_priv->via_irqs;
int i;
@@ -119,18 +112,18 @@ irqreturn_t via_driver_irq_handler(int irq, void *arg)
if (status & VIA_IRQ_VBLANK_PENDING) {
atomic_inc(&dev_priv->vbl_received);
if (!(atomic_read(&dev_priv->vbl_received) & 0x0F)) {
- do_gettimeofday(&cur_vblank);
+ cur_vblank = ktime_get();
if (dev_priv->last_vblank_valid) {
- dev_priv->usec_per_vblank =
- time_diff(&cur_vblank,
- &dev_priv->last_vblank) >> 4;
+ dev_priv->nsec_per_vblank =
+ ktime_sub(cur_vblank,
+ dev_priv->last_vblank) >> 4;
}
dev_priv->last_vblank = cur_vblank;
dev_priv->last_vblank_valid = 1;
}
if (!(atomic_read(&dev_priv->vbl_received) & 0xFF)) {
- DRM_DEBUG("US per vblank is: %u\n",
- dev_priv->usec_per_vblank);
+ DRM_DEBUG("nsec per vblank is: %llu\n",
+ ktime_to_ns(dev_priv->nsec_per_vblank));
}
drm_handle_vblank(dev, 0);
handled = 1;
--
2.9.0
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