From de7e8bd01a241103c141801479e0bda786b76290 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sat, 4 Nov 2017 22:20:08 +0100 Subject: drm: via: use ktime_get() instead of do_gettimeofday 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 Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20171104212131.2939989-1-arnd@arndb.de --- drivers/gpu/drm/via/via_drv.h | 4 ++-- drivers/gpu/drm/via/via_irq.c | 21 +++++++-------------- 2 files changed, 9 insertions(+), 16 deletions(-) (limited to 'drivers/gpu/drm/via') 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; -- cgit v1.2.3 From 44a2d56429bc9d1f9edd56761bfb504ed68fef01 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 27 Nov 2017 12:17:03 +0100 Subject: drm/via: use monotonic time for VIA_WAIT_IRQ The normal DRM vblank interrupt events started using monotonic times in commit c61eef726a78 ("drm: add support for monotonic vblank timestamps"), which is useful for a number of reasons, including the possible y2038 overflow. The VIA_WAIT_IRQ ioctl uses the same drm_wait_vblank_reply as DRM_IOCTL_WAIT_VBLANK, but still uses wall-clock time. This converts it to using monotonic time as well, which is more consistent, and avoids problems with the y2038 overflow as well as synchronization issues when the real time skips. I could not find the matching user space that calls the VIA_WAIT_IRQ ioctl to verify that this is safe, but it very likely is. Please either test or review the user space side before applying this. Signed-off-by: Arnd Bergmann Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20171127111728.1710742-1-arnd@arndb.de --- drivers/gpu/drm/via/via_irq.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/via') diff --git a/drivers/gpu/drm/via/via_irq.c b/drivers/gpu/drm/via/via_irq.c index 24e71578af4d..c96830ccc0ec 100644 --- a/drivers/gpu/drm/via/via_irq.c +++ b/drivers/gpu/drm/via/via_irq.c @@ -343,7 +343,7 @@ void via_driver_irq_uninstall(struct drm_device *dev) int via_wait_irq(struct drm_device *dev, void *data, struct drm_file *file_priv) { drm_via_irqwait_t *irqwait = data; - struct timeval now; + struct timespec64 now; int ret = 0; drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private; drm_via_irq_t *cur_irq = dev_priv->via_irqs; @@ -377,9 +377,9 @@ int via_wait_irq(struct drm_device *dev, void *data, struct drm_file *file_priv) ret = via_driver_irq_wait(dev, irqwait->request.irq, force_sequence, &irqwait->request.sequence); - do_gettimeofday(&now); + ktime_get_ts64(&now); irqwait->reply.tval_sec = now.tv_sec; - irqwait->reply.tval_usec = now.tv_usec; + irqwait->reply.tval_usec = now.tv_nsec / NSEC_PER_USEC; return ret; } -- cgit v1.2.3