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

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index d2d92cc4b420003f1c4c8d2dc7510e6e1174fef2..53d4afe15278c946a3bc2f27ed063369ea9488e2 100644 (file)
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -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)