[5/5] drm/rockchip: Add dmc notifier in vop driver
diff mbox

Message ID 1472769085-20715-6-git-send-email-hl@rock-chips.com
State New
Headers show

Commit Message

huang lin Sept. 1, 2016, 10:31 p.m. UTC
when in ddr frequency scaling process, vop can not do enable or
disable operation, since in dcf we check vop clock to see whether
vop work. If vop work, dcf do ddr frequency scaling when vop
in vblank status, and we need to read vop register to check whether
vop go into vblank status. If vop not work, dcf can do ddr frequency
any time. So when do ddr frequency scaling, you disabled or enable
vop, there may two bad thing happen: 1, the panel flicker(when vop from
disable status change to enable). 2, kernel hang (when vop from enable
status change to disable, dcf need to read vblank status, but if you disable
vop clock, it can not get the status, it will lead soc dead) So we need
register to devfreq notifier, and we can get the dmc status. Also, when
there have two vop enabled, we need to disable dmc, since dcf only base
on one vop vblank time, so the other panel will flicker when do ddr
frequency scaling.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
---
Changes in v8:
- None

Changes in v7:
- None

Changes in v6:
- fix a build error

Changes in v5:
- improve some nits

Changes in v4:
- register notifier to devfreq_register_notifier
- use DEVFREQ_PRECHANGE and DEVFREQ_POSTCHANGE to get dmc status
- when two vop enable, disable dmc
- when two vop back to one vop, enable dmc

Changes in v3:
- when do vop eanble/disable, dmc will wait until it finish

Changes in v2:
- None

Changes in v1:
- use wait_event instead usleep

 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 116 ++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

Comments

kbuild test robot Sept. 2, 2016, 12:34 a.m. UTC | #1
Hi Lin,

[auto build test ERROR on next-20160825]
[cannot apply to rockchip/for-next devfreq/for-rafael linus/master v4.8-rc4 v4.8-rc3 v4.8-rc2 v4.8-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
[Suggest to use git(>=2.9.0) format-patch --base=<commit> (or --base=auto for convenience) to record what (public, well-known) commit your patch series was built on]
[Check https://git-scm.com/docs/git-format-patch for more information]

url:    https://github.com/0day-ci/linux/commits/Lin-Huang/rk3399-support-ddr-frequency-scaling/20160902-063701
config: arm-multi_v7_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 5.4.0-6) 5.4.0 20160609
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm 

All error/warnings (new ones prefixed by >>):

   In file included from drivers/gpu/drm/rockchip/rockchip_drm_vop.c:23:0:
   include/linux/devfreq-event.h:190:21: error: redefinition of 'devfreq_event_get_drvdata'
    static inline void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev)
                        ^
   include/linux/devfreq-event.h:151:21: note: previous definition of 'devfreq_event_get_drvdata' was here
    static inline void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev)
                        ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c: In function 'vop_crtc_disable':
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:653:13: error: invalid storage class for function 'vop_plane_destroy'
    static void vop_plane_destroy(struct drm_plane *plane)
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:653:1: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
    static void vop_plane_destroy(struct drm_plane *plane)
    ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:658:12: error: invalid storage class for function 'vop_plane_prepare_fb'
    static int vop_plane_prepare_fb(struct drm_plane *plane,
               ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:667:13: error: invalid storage class for function 'vop_plane_cleanup_fb'
    static void vop_plane_cleanup_fb(struct drm_plane *plane,
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:674:12: error: invalid storage class for function 'vop_plane_atomic_check'
    static int vop_plane_atomic_check(struct drm_plane *plane,
               ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:731:13: error: invalid storage class for function 'vop_plane_atomic_disable'
    static void vop_plane_atomic_disable(struct drm_plane *plane,
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:756:13: error: invalid storage class for function 'vop_plane_atomic_update'
    static void vop_plane_atomic_update(struct drm_plane *plane,
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:866:16: error: initializer element is not constant
     .prepare_fb = vop_plane_prepare_fb,
                   ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:866:16: note: (near initialization for 'plane_helper_funcs.prepare_fb')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:867:16: error: initializer element is not constant
     .cleanup_fb = vop_plane_cleanup_fb,
                   ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:867:16: note: (near initialization for 'plane_helper_funcs.cleanup_fb')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:868:18: error: initializer element is not constant
     .atomic_check = vop_plane_atomic_check,
                     ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:868:18: note: (near initialization for 'plane_helper_funcs.atomic_check')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:869:19: error: initializer element is not constant
     .atomic_update = vop_plane_atomic_update,
                      ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:869:19: note: (near initialization for 'plane_helper_funcs.atomic_update')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:870:20: error: initializer element is not constant
     .atomic_disable = vop_plane_atomic_disable,
                       ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:870:20: note: (near initialization for 'plane_helper_funcs.atomic_disable')
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:873:13: error: invalid storage class for function 'vop_atomic_plane_reset'
    static void vop_atomic_plane_reset(struct drm_plane *plane)
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:891:1: error: invalid storage class for function 'vop_atomic_plane_duplicate_state'
    vop_atomic_plane_duplicate_state(struct drm_plane *plane)
    ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:911:13: error: invalid storage class for function 'vop_atomic_plane_destroy_state'
    static void vop_atomic_plane_destroy_state(struct drm_plane *plane,
                ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:924:13: error: initializer element is not constant
     .destroy = vop_plane_destroy,
                ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:924:13: note: (near initialization for 'vop_plane_funcs.destroy')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:925:11: error: initializer element is not constant
     .reset = vop_atomic_plane_reset,
              ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:925:11: note: (near initialization for 'vop_plane_funcs.reset')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:926:28: error: initializer element is not constant
     .atomic_duplicate_state = vop_atomic_plane_duplicate_state,
                               ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:926:28: note: (near initialization for 'vop_plane_funcs.atomic_duplicate_state')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:927:26: error: initializer element is not constant
     .atomic_destroy_state = vop_atomic_plane_destroy_state,
                             ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:927:26: note: (near initialization for 'vop_plane_funcs.atomic_destroy_state')
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:930:12: error: invalid storage class for function 'vop_crtc_enable_vblank'
    static int vop_crtc_enable_vblank(struct drm_crtc *crtc)
               ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:947:13: error: invalid storage class for function 'vop_crtc_disable_vblank'
    static void vop_crtc_disable_vblank(struct drm_crtc *crtc)
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:962:13: error: invalid storage class for function 'vop_crtc_wait_for_update'
    static void vop_crtc_wait_for_update(struct drm_crtc *crtc)
                ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:971:19: error: initializer element is not constant
     .enable_vblank = vop_crtc_enable_vblank,
                      ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:971:19: note: (near initialization for 'private_crtc_funcs.enable_vblank')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:972:20: error: initializer element is not constant
     .disable_vblank = vop_crtc_disable_vblank,
                       ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:972:20: note: (near initialization for 'private_crtc_funcs.disable_vblank')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:973:21: error: initializer element is not constant
     .wait_for_update = vop_crtc_wait_for_update,
                        ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:973:21: note: (near initialization for 'private_crtc_funcs.wait_for_update')
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:976:13: error: invalid storage class for function 'vop_crtc_mode_fixup'
    static bool vop_crtc_mode_fixup(struct drm_crtc *crtc,
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:988:13: error: invalid storage class for function 'vop_crtc_enable'
    static void vop_crtc_enable(struct drm_crtc *crtc)
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1090:13: error: invalid storage class for function 'vop_crtc_atomic_flush'
    static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1105:13: error: invalid storage class for function 'vop_crtc_atomic_begin'
    static void vop_crtc_atomic_begin(struct drm_crtc *crtc,
                ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1122:12: error: initializer element is not constant
     .enable = vop_crtc_enable,
               ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1122:12: note: (near initialization for 'vop_crtc_helper_funcs.enable')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1124:16: error: initializer element is not constant
     .mode_fixup = vop_crtc_mode_fixup,
                   ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1124:16: note: (near initialization for 'vop_crtc_helper_funcs.mode_fixup')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1125:18: error: initializer element is not constant
     .atomic_flush = vop_crtc_atomic_flush,
                     ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1125:18: note: (near initialization for 'vop_crtc_helper_funcs.atomic_flush')
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1126:18: error: initializer element is not constant
     .atomic_begin = vop_crtc_atomic_begin,
                     ^
   drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1126:18: note: (near initialization for 'vop_crtc_helper_funcs.atomic_begin')
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1129:13: error: invalid storage class for function 'vop_crtc_destroy'
    static void vop_crtc_destroy(struct drm_crtc *crtc)
                ^
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c:1134:13: error: invalid storage class for function 'vop_crtc_reset'
    static void vop_crtc_reset(struct drm_crtc *crtc)
                ^

vim +/vop_plane_destroy +653 drivers/gpu/drm/rockchip/rockchip_drm_vop.c

4bb85264 Lin Huang     2016-09-02  647  		if (vop->devfreq_event_dev)
4bb85264 Lin Huang     2016-09-02  648  			devfreq_event_enable_edev(vop->devfreq_event_dev);
4bb85264 Lin Huang     2016-09-02  649  		devfreq_resume_device(vop->devfreq);
893b6cad Daniel Vetter 2016-06-08  650  	}
2048e328 Mark Yao      2014-08-22  651  }
2048e328 Mark Yao      2014-08-22  652  
63ebb9fa Mark Yao      2015-11-30 @653  static void vop_plane_destroy(struct drm_plane *plane)
2048e328 Mark Yao      2014-08-22  654  {
63ebb9fa Mark Yao      2015-11-30  655  	drm_plane_cleanup(plane);
2048e328 Mark Yao      2014-08-22  656  }
2048e328 Mark Yao      2014-08-22  657  
44d0237a Mark Yao      2016-04-29 @658  static int vop_plane_prepare_fb(struct drm_plane *plane,
1832040d Chris Wilson  2016-08-18  659  				struct drm_plane_state *new_state)
44d0237a Mark Yao      2016-04-29  660  {
44d0237a Mark Yao      2016-04-29  661  	if (plane->state->fb)
44d0237a Mark Yao      2016-04-29  662  		drm_framebuffer_reference(plane->state->fb);
44d0237a Mark Yao      2016-04-29  663  
44d0237a Mark Yao      2016-04-29  664  	return 0;
44d0237a Mark Yao      2016-04-29  665  }
44d0237a Mark Yao      2016-04-29  666  
44d0237a Mark Yao      2016-04-29 @667  static void vop_plane_cleanup_fb(struct drm_plane *plane,
1832040d Chris Wilson  2016-08-18  668  				 struct drm_plane_state *old_state)
44d0237a Mark Yao      2016-04-29  669  {
44d0237a Mark Yao      2016-04-29  670  	if (old_state->fb)
44d0237a Mark Yao      2016-04-29  671  		drm_framebuffer_unreference(old_state->fb);
44d0237a Mark Yao      2016-04-29  672  }
44d0237a Mark Yao      2016-04-29  673  
63ebb9fa Mark Yao      2015-11-30 @674  static int vop_plane_atomic_check(struct drm_plane *plane,
63ebb9fa Mark Yao      2015-11-30  675  			   struct drm_plane_state *state)
2048e328 Mark Yao      2014-08-22  676  {
63ebb9fa Mark Yao      2015-11-30  677  	struct drm_crtc *crtc = state->crtc;
92915da6 John Keeping  2016-03-04  678  	struct drm_crtc_state *crtc_state;
63ebb9fa Mark Yao      2015-11-30  679  	struct drm_framebuffer *fb = state->fb;
2048e328 Mark Yao      2014-08-22  680  	struct vop_win *vop_win = to_vop_win(plane);
63ebb9fa Mark Yao      2015-11-30  681  	struct vop_plane_state *vop_plane_state = to_vop_plane_state(state);
2048e328 Mark Yao      2014-08-22  682  	const struct vop_win_data *win = vop_win->data;
2048e328 Mark Yao      2014-08-22  683  	int ret;
63ebb9fa Mark Yao      2015-11-30  684  	struct drm_rect clip;
4c156c21 Mark Yao      2015-06-26  685  	int min_scale = win->phy->scl ? FRAC_16_16(1, 8) :
4c156c21 Mark Yao      2015-06-26  686  					DRM_PLANE_HELPER_NO_SCALING;
4c156c21 Mark Yao      2015-06-26  687  	int max_scale = win->phy->scl ? FRAC_16_16(8, 1) :
4c156c21 Mark Yao      2015-06-26  688  					DRM_PLANE_HELPER_NO_SCALING;
2048e328 Mark Yao      2014-08-22  689  
63ebb9fa Mark Yao      2015-11-30  690  	if (!crtc || !fb)
63ebb9fa Mark Yao      2015-11-30  691  		goto out_disable;
92915da6 John Keeping  2016-03-04  692  
92915da6 John Keeping  2016-03-04  693  	crtc_state = drm_atomic_get_existing_crtc_state(state->state, crtc);
92915da6 John Keeping  2016-03-04  694  	if (WARN_ON(!crtc_state))
92915da6 John Keeping  2016-03-04  695  		return -EINVAL;
92915da6 John Keeping  2016-03-04  696  
63ebb9fa Mark Yao      2015-11-30  697  	clip.x1 = 0;
63ebb9fa Mark Yao      2015-11-30  698  	clip.y1 = 0;
92915da6 John Keeping  2016-03-04  699  	clip.x2 = crtc_state->adjusted_mode.hdisplay;
92915da6 John Keeping  2016-03-04  700  	clip.y2 = crtc_state->adjusted_mode.vdisplay;
63ebb9fa Mark Yao      2015-11-30  701  
f9b96be0 Ville Syrjälä 2016-07-26  702  	ret = drm_plane_helper_check_state(state, &clip,
f9b96be0 Ville Syrjälä 2016-07-26  703  					   min_scale, max_scale,
f9b96be0 Ville Syrjälä 2016-07-26  704  					   true, true);
2048e328 Mark Yao      2014-08-22  705  	if (ret)
2048e328 Mark Yao      2014-08-22  706  		return ret;
2048e328 Mark Yao      2014-08-22  707  
f9b96be0 Ville Syrjälä 2016-07-26  708  	if (!state->visible)
63ebb9fa Mark Yao      2015-11-30  709  		goto out_disable;
84c7f8ca Mark Yao      2015-07-20  710  
63ebb9fa Mark Yao      2015-11-30  711  	vop_plane_state->format = vop_convert_format(fb->pixel_format);
63ebb9fa Mark Yao      2015-11-30  712  	if (vop_plane_state->format < 0)
63ebb9fa Mark Yao      2015-11-30  713  		return vop_plane_state->format;
2048e328 Mark Yao      2014-08-22  714  
84c7f8ca Mark Yao      2015-07-20  715  	/*
84c7f8ca Mark Yao      2015-07-20  716  	 * Src.x1 can be odd when do clip, but yuv plane start point
84c7f8ca Mark Yao      2015-07-20  717  	 * need align with 2 pixel.
84c7f8ca Mark Yao      2015-07-20  718  	 */
f9b96be0 Ville Syrjälä 2016-07-26  719  	if (is_yuv_support(fb->pixel_format) && ((state->src.x1 >> 16) % 2))
63ebb9fa Mark Yao      2015-11-30  720  		return -EINVAL;
84c7f8ca Mark Yao      2015-07-20  721  
63ebb9fa Mark Yao      2015-11-30  722  	vop_plane_state->enable = true;
2048e328 Mark Yao      2014-08-22  723  
63ebb9fa Mark Yao      2015-11-30  724  	return 0;
2048e328 Mark Yao      2014-08-22  725  
63ebb9fa Mark Yao      2015-11-30  726  out_disable:
63ebb9fa Mark Yao      2015-11-30  727  	vop_plane_state->enable = false;
63ebb9fa Mark Yao      2015-11-30  728  	return 0;
63ebb9fa Mark Yao      2015-11-30  729  }
2048e328 Mark Yao      2014-08-22  730  
63ebb9fa Mark Yao      2015-11-30 @731  static void vop_plane_atomic_disable(struct drm_plane *plane,
63ebb9fa Mark Yao      2015-11-30  732  				     struct drm_plane_state *old_state)
63ebb9fa Mark Yao      2015-11-30  733  {
63ebb9fa Mark Yao      2015-11-30  734  	struct vop_plane_state *vop_plane_state = to_vop_plane_state(old_state);
63ebb9fa Mark Yao      2015-11-30  735  	struct vop_win *vop_win = to_vop_win(plane);
63ebb9fa Mark Yao      2015-11-30  736  	const struct vop_win_data *win = vop_win->data;
63ebb9fa Mark Yao      2015-11-30  737  	struct vop *vop = to_vop(old_state->crtc);
2048e328 Mark Yao      2014-08-22  738  
63ebb9fa Mark Yao      2015-11-30  739  	if (!old_state->crtc)
63ebb9fa Mark Yao      2015-11-30  740  		return;
84c7f8ca Mark Yao      2015-07-20  741  
4f9d39a7 Daniel Vetter 2016-06-08  742  	spin_lock_irq(&plane->dev->event_lock);
4f9d39a7 Daniel Vetter 2016-06-08  743  	vop_win->enable = false;
4f9d39a7 Daniel Vetter 2016-06-08  744  	vop_win->yrgb_mst = 0;
4f9d39a7 Daniel Vetter 2016-06-08  745  	spin_unlock_irq(&plane->dev->event_lock);
4f9d39a7 Daniel Vetter 2016-06-08  746  
63ebb9fa Mark Yao      2015-11-30  747  	spin_lock(&vop->reg_lock);
63ebb9fa Mark Yao      2015-11-30  748  
63ebb9fa Mark Yao      2015-11-30  749  	VOP_WIN_SET(vop, win, enable, 0);
84c7f8ca Mark Yao      2015-07-20  750  
63ebb9fa Mark Yao      2015-11-30  751  	spin_unlock(&vop->reg_lock);
84c7f8ca Mark Yao      2015-07-20  752  
63ebb9fa Mark Yao      2015-11-30  753  	vop_plane_state->enable = false;
84c7f8ca Mark Yao      2015-07-20  754  }
84c7f8ca Mark Yao      2015-07-20  755  
63ebb9fa Mark Yao      2015-11-30 @756  static void vop_plane_atomic_update(struct drm_plane *plane,
63ebb9fa Mark Yao      2015-11-30  757  		struct drm_plane_state *old_state)
63ebb9fa Mark Yao      2015-11-30  758  {
63ebb9fa Mark Yao      2015-11-30  759  	struct drm_plane_state *state = plane->state;

:::::: The code at line 653 was first introduced by commit
:::::: 63ebb9fa7ff06d194362ed4a5d0a31ac7612a89c drm/rockchip: Convert to support atomic API

:::::: TO: Mark Yao <mark.yao@rock-chips.com>
:::::: CC: Mark Yao <mark.yao@rock-chips.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch
diff mbox

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index efbc41a..a73f3aa 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -19,6 +19,8 @@ 
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_plane_helper.h>
 
+#include <linux/devfreq.h>
+#include <linux/devfreq-event.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -118,6 +120,13 @@  struct vop {
 
 	const struct vop_data *data;
 
+	struct devfreq *devfreq;
+	struct devfreq_event_dev *devfreq_event_dev;
+	struct notifier_block dmc_nb;
+	int dmc_in_process;
+	int vop_switch_status;
+	wait_queue_head_t wait_dmc_queue;
+	wait_queue_head_t wait_vop_switch_queue;
 	uint32_t *regsbak;
 	void __iomem *regs;
 
@@ -428,11 +437,47 @@  static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
 	spin_unlock_irqrestore(&vop->irq_lock, flags);
 }
 
+static int dmc_notify(struct notifier_block *nb, unsigned long event,
+		      void *data)
+{
+	struct vop *vop = container_of(nb, struct vop, dmc_nb);
+
+	if (event == DEVFREQ_PRECHANGE) {
+		/*
+		 * check if vop in enable or disable process,
+		 * if yes, wait until it finishes, use 200ms as
+		 * timeout.
+		 */
+		if (!wait_event_timeout(vop->wait_vop_switch_queue,
+					!vop->vop_switch_status, HZ / 5))
+			dev_warn(vop->dev,
+				 "Timeout waiting for vop swtich status\n");
+		vop->dmc_in_process = 1;
+	} else if (event == DEVFREQ_POSTCHANGE) {
+		vop->dmc_in_process = 0;
+		wake_up(&vop->wait_dmc_queue);
+	}
+
+	return NOTIFY_OK;
+}
+
 static int vop_enable(struct drm_crtc *crtc)
 {
 	struct vop *vop = to_vop(crtc);
+	int num_enabled_crtc = 0;
 	int ret;
 
+	/*
+	 * if in dmc scaling frequency process, wait until it finishes
+	 * use 200ms as timeout time.
+	 */
+	if (!wait_event_timeout(vop->wait_dmc_queue,
+				!vop->dmc_in_process, HZ / 5))
+		dev_warn(vop->dev,
+			 "Timeout waiting for dmc when vop enable\n");
+
+	vop->vop_switch_status = 1;
+
 	ret = pm_runtime_get_sync(vop->dev);
 	if (ret < 0) {
 		dev_err(vop->dev, "failed to get pm runtime: %d\n", ret);
@@ -479,6 +524,21 @@  static int vop_enable(struct drm_crtc *crtc)
 
 	drm_crtc_vblank_on(crtc);
 
+	vop->vop_switch_status = 0;
+	wake_up(&vop->wait_vop_switch_queue);
+
+	/* check how many VOPs in use now */
+	drm_for_each_crtc(crtc, vop->drm_dev) {
+		if (crtc->state->enable)
+			num_enabled_crtc++;
+	}
+
+	/* if enable two vop, need to disable dmc */
+	if ((num_enabled_crtc > 1) && vop->devfreq) {
+		if (vop->devfreq_event_dev)
+			devfreq_event_disable_edev(vop->devfreq_event_dev);
+		devfreq_suspend_device(vop->devfreq);
+	}
 	return 0;
 
 err_disable_aclk:
@@ -489,17 +549,31 @@  err_disable_hclk:
 	clk_disable(vop->hclk);
 err_put_pm_runtime:
 	pm_runtime_put_sync(vop->dev);
+	vop->vop_switch_status = 0;
+	wake_up(&vop->wait_vop_switch_queue);
 	return ret;
 }
 
 static void vop_crtc_disable(struct drm_crtc *crtc)
 {
 	struct vop *vop = to_vop(crtc);
+	int num_enabled_crtc = 0;
 	int i;
 
 	WARN_ON(vop->event);
 
 	/*
+	 * if in dmc scaling frequency process, wait until it finish
+	 * use 200ms as timeout time.
+	 */
+	if (!wait_event_timeout(vop->wait_dmc_queue,
+				!vop->dmc_in_process, HZ / 5))
+		dev_warn(vop->dev,
+			 "Timeout waiting for dmc when vop disable\n");
+
+	vop->vop_switch_status = 1;
+
+	/*
 	 * We need to make sure that all windows are disabled before we
 	 * disable that crtc. Otherwise we might try to scan from a destroyed
 	 * buffer later.
@@ -555,6 +629,24 @@  static void vop_crtc_disable(struct drm_crtc *crtc)
 		spin_unlock_irq(&crtc->dev->event_lock);
 
 		crtc->state->event = NULL;
+
+	vop->vop_switch_status = 0;
+	wake_up(&vop->wait_vop_switch_queue);
+
+	/* check how many VOPs in use now */
+	drm_for_each_crtc(crtc, vop->drm_dev) {
+		if (crtc->state->enable)
+			num_enabled_crtc++;
+	}
+
+	/*
+	 * if num_enabled_crtc = 1 now, it means 2 vop enabled
+	 * change to 1 vop enabled  need to enable dmc again.
+	 */
+	if ((num_enabled_crtc == 1) && vop->devfreq) {
+		if (vop->devfreq_event_dev)
+			devfreq_event_enable_edev(vop->devfreq_event_dev);
+		devfreq_resume_device(vop->devfreq);
 	}
 }
 
@@ -1413,6 +1505,8 @@  static int vop_bind(struct device *dev, struct device *master, void *data)
 	struct drm_device *drm_dev = data;
 	struct vop *vop;
 	struct resource *res;
+	struct devfreq *devfreq;
+	struct devfreq_event_dev *event_dev;
 	size_t alloc_size;
 	int ret, irq;
 
@@ -1474,6 +1568,28 @@  static int vop_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 
 	pm_runtime_enable(&pdev->dev);
+
+	init_waitqueue_head(&vop->wait_vop_switch_queue);
+	vop->vop_switch_status = 0;
+	init_waitqueue_head(&vop->wait_dmc_queue);
+	vop->dmc_in_process = 0;
+
+	devfreq = devfreq_get_devfreq_by_phandle(dev, 0);
+	if (IS_ERR(devfreq))
+		goto out;
+
+	vop->devfreq = devfreq;
+	vop->dmc_nb.notifier_call = dmc_notify;
+	devfreq_register_notifier(vop->devfreq, &vop->dmc_nb,
+				  DEVFREQ_TRANSITION_NOTIFIER);
+
+	event_dev = devfreq_event_get_edev_by_phandle(vop->devfreq->dev.parent,
+						      0);
+	if (IS_ERR(event_dev))
+		goto out;
+
+	vop->devfreq_event_dev = event_dev;
+out:
 	return 0;
 }