CHROMIUM: drm/rockchip: Clear interrupt status bits before enabling

The enable register only masks the raw status bits to signal CPU
interrupt only for enabled interrupts. The status bits are activated
regardless of the enable register. This means that we might have an old
interrupt event queued, which we are not interested in. To avoid getting
a spurious interrupt signalled, we have to clear the old bit before we
update the enable register.

BUG=chrome-os-partner:56378
BUG=chrome-os-partner:56580
TEST=while true; do backlight_dbus_tool --set --percent=0 && sleep 8 && backlight_dbus_tool --set --percent=100 && sleep 3 ; done

Change-Id: I1b8286097f3ba102663ee3a7566fd96492e12d26
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/382973
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index b10476fca40b373345af4665310e75a44d8c20c5..a80deb50d27d22a426b02e2fc46c23336e0c30b5 100644 (file)
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -664,6 +664,7 @@ static void vop_dsp_hold_valid_irq_enable(struct vop *vop)
 
        spin_lock_irqsave(&vop->irq_lock, flags);
 
+       VOP_INTR_SET_TYPE(vop, clear, DSP_HOLD_VALID_INTR, 1);
        VOP_INTR_SET_TYPE(vop, enable, DSP_HOLD_VALID_INTR, 1);
 
        spin_unlock_irqrestore(&vop->irq_lock, flags);
@@ -726,6 +727,7 @@ static void vop_line_flag_irq_enable(struct vop *vop, int line_num)
        spin_lock_irqsave(&vop->irq_lock, flags);
 
        VOP_INTR_SET(vop, line_flag_num[0], line_num);
+       VOP_INTR_SET_TYPE(vop, clear, LINE_FLAG_INTR, 1);
        VOP_INTR_SET_TYPE(vop, enable, LINE_FLAG_INTR, 1);
 
        spin_unlock_irqrestore(&vop->irq_lock, flags);
@@ -1240,6 +1242,7 @@ static int vop_crtc_enable_vblank(struct drm_crtc *crtc)
 
        spin_lock_irqsave(&vop->irq_lock, flags);
 
+       VOP_INTR_SET_TYPE(vop, clear, FS_INTR, 1);
        VOP_INTR_SET_TYPE(vop, enable, FS_INTR, 1);
 
        spin_unlock_irqrestore(&vop->irq_lock, flags);