spin_lock_irqsave and spin_unlock_irqrestore is inteded to be called from a context where it is unknown if interrupts are enabled or disabled (such as interrupt handlers). From a process context, we should call spin_lock_irq and spin_unlock_irq, that avoids the costly pushf and popf instructions.
Signed-off-by: Mikulas Patocka mpatocka@redhat.com
--- drivers/gpu/drm/udl/udl_main.c | 10 ++++------ drivers/gpu/drm/udl/udl_modeset.c | 5 ++--- 2 files changed, 6 insertions(+), 9 deletions(-)
Index: linux-4.16.12/drivers/gpu/drm/udl/udl_main.c =================================================================== --- linux-4.16.12.orig/drivers/gpu/drm/udl/udl_main.c 2018-05-31 11:17:01.000000000 +0200 +++ linux-4.16.12/drivers/gpu/drm/udl/udl_main.c 2018-05-31 11:17:01.000000000 +0200 @@ -170,7 +170,6 @@ static void udl_free_urb_list(struct drm struct list_head *node; struct urb_node *unode; struct urb *urb; - unsigned long flags;
DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
@@ -178,12 +177,12 @@ static void udl_free_urb_list(struct drm while (count--) { down(&udl->urbs.limit_sem);
- spin_lock_irqsave(&udl->urbs.lock, flags); + spin_lock_irq(&udl->urbs.lock);
node = udl->urbs.list.next; /* have reserved one with sem */ list_del_init(node);
- spin_unlock_irqrestore(&udl->urbs.lock, flags); + spin_unlock_irq(&udl->urbs.lock);
unode = list_entry(node, struct urb_node, entry); urb = unode->urb; @@ -268,7 +267,6 @@ struct urb *udl_get_urb(struct drm_devic struct list_head *entry; struct urb_node *unode; struct urb *urb = NULL; - unsigned long flags;
/* Wait for an in-flight buffer to complete and get re-queued */ ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT); @@ -279,14 +277,14 @@ struct urb *udl_get_urb(struct drm_devic goto error; }
- spin_lock_irqsave(&udl->urbs.lock, flags); + spin_lock_irq(&udl->urbs.lock);
BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */ entry = udl->urbs.list.next; list_del_init(entry); udl->urbs.available--;
- spin_unlock_irqrestore(&udl->urbs.lock, flags); + spin_unlock_irq(&udl->urbs.lock);
unode = list_entry(entry, struct urb_node, entry); urb = unode->urb; Index: linux-4.16.12/drivers/gpu/drm/udl/udl_modeset.c =================================================================== --- linux-4.16.12.orig/drivers/gpu/drm/udl/udl_modeset.c 2018-05-31 11:17:01.000000000 +0200 +++ linux-4.16.12/drivers/gpu/drm/udl/udl_modeset.c 2018-05-31 11:17:01.000000000 +0200 @@ -366,7 +366,6 @@ static int udl_crtc_page_flip(struct drm { struct udl_framebuffer *ufb = to_udl_fb(fb); struct drm_device *dev = crtc->dev; - unsigned long flags;
struct drm_framebuffer *old_fb = crtc->primary->fb; if (old_fb) { @@ -377,10 +376,10 @@ static int udl_crtc_page_flip(struct drm
udl_handle_damage(ufb, 0, 0, fb->width, fb->height);
- spin_lock_irqsave(&dev->event_lock, flags); + spin_lock_irq(&dev->event_lock); if (event) drm_crtc_send_vblank_event(crtc, event); - spin_unlock_irqrestore(&dev->event_lock, flags); + spin_unlock_irq(&dev->event_lock); crtc->primary->fb = fb;
return 0;