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drm/rockchip: Don't use spin_lock_irqsave in interrupt context 

The rockchip DRM driver is quite careful to disable interrupts
when taking a lock that is also taken in interrupt context,
which is a good thing.

What is a bit over the top is to use spin_lock_irqsave when
already in interrupt context, as you cannot take another
interrupt again, and disabling interrupt is just pure
overhead.

Switching to the non _irqsave version in interrupt context is
more logical, and less heavy handed.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180220130120.5254-4-marc.zyngier@arm.com
This commit is contained in:
Marc Zyngier 2018-02-20 13:01:20 +00:00 committed by Heiko Stuebner
parent 76f1416e64
commit 1c85f2fa68
1 changed files with 4 additions and 6 deletions
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10
drivers/gpu/drm/rockchip/rockchip_drm_vop.c
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@ -1147,15 +1147,14 @@ static void vop_handle_vblank(struct vop *vop)
{
struct drm_device *drm = vop->drm_dev;
struct drm_crtc *crtc = &vop->crtc;
unsigned long flags;
spin_lock_irqsave(&drm->event_lock, flags);
spin_lock(&drm->event_lock);
if (vop->event) {
drm_crtc_send_vblank_event(crtc, vop->event);
drm_crtc_vblank_put(crtc);
vop->event = NULL;
}
spin_unlock_irqrestore(&drm->event_lock, flags);
spin_unlock(&drm->event_lock);
if (test_and_clear_bit(VOP_PENDING_FB_UNREF, &vop->pending))
drm_flip_work_commit(&vop->fb_unref_work, system_unbound_wq);
@ -1166,21 +1165,20 @@ static irqreturn_t vop_isr(int irq, void *data)
struct vop *vop = data;
struct drm_crtc *crtc = &vop->crtc;
uint32_t active_irqs;
unsigned long flags;
int ret = IRQ_NONE;
/*
* interrupt register has interrupt status, enable and clear bits, we
* must hold irq_lock to avoid a race with enable/disable_vblank().
*/
spin_lock_irqsave(&vop->irq_lock, flags);
spin_lock(&vop->irq_lock);
active_irqs = VOP_INTR_GET_TYPE(vop, status, INTR_MASK);
/* Clear all active interrupt sources */
if (active_irqs)
VOP_INTR_SET_TYPE(vop, clear, active_irqs, 1);
spin_unlock_irqrestore(&vop->irq_lock, flags);
spin_unlock(&vop->irq_lock);
/* This is expected for vop iommu irqs, since the irq is shared */
if (!active_irqs)