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Commit 1c85f2fa authored by Marc Zyngier's avatar Marc Zyngier Committed by Heiko Stuebner
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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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180220130120.5254-4-marc.zyngier@arm.com
parent 76f1416e

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

+4 −6
Original line number Diff line number Diff line
@@ -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)