[PATCH 4.8 22/96] drm/amd/amdgpu: enable GUI idle INT after enabling CGCG

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arindam Nath <arindam.nath@xxxxxxx>

commit dd31ae9ac933636c3712b7dd0f6152c1d71f81fe upstream.

GUI idle interrupts should be enabled only after we
have enabled coarse grain clock gating (CGCG). This
prevents GFX engine generating idle interrupt even
though CGCG is not completely enabled.

Most of the time this goes un-noticed, but on some
Stoney ASICs this results in GFX engine hang after
system resumes from suspend. The issue is not
particular to Stoney though and could have occured
on any ASIC. The patch fixes this issue.

Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
Reported-by: Sunil Uttarwar <Sunil.Uttarwar1@xxxxxxx>
Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -5735,29 +5735,24 @@ static void gfx_v8_0_update_coarse_grain
 	adev->gfx.rlc.funcs->enter_safe_mode(adev);
 
 	if (enable && (adev->cg_flags & AMD_CG_SUPPORT_GFX_CGCG)) {
-		/* 1 enable cntx_empty_int_enable/cntx_busy_int_enable/
-		 * Cmp_busy/GFX_Idle interrupts
-		 */
-		gfx_v8_0_enable_gui_idle_interrupt(adev, true);
-
 		temp1 = data1 =	RREG32(mmRLC_CGTT_MGCG_OVERRIDE);
 		data1 &= ~RLC_CGTT_MGCG_OVERRIDE__CGCG_MASK;
 		if (temp1 != data1)
 			WREG32(mmRLC_CGTT_MGCG_OVERRIDE, data1);
 
-		/* 2 wait for RLC_SERDES_CU_MASTER & RLC_SERDES_NONCU_MASTER idle */
+		/* : wait for RLC_SERDES_CU_MASTER & RLC_SERDES_NONCU_MASTER idle */
 		gfx_v8_0_wait_for_rlc_serdes(adev);
 
-		/* 3 - clear cgcg override */
+		/* 2 - clear cgcg override */
 		gfx_v8_0_send_serdes_cmd(adev, BPM_REG_CGCG_OVERRIDE, CLE_BPM_SERDES_CMD);
 
 		/* wait for RLC_SERDES_CU_MASTER & RLC_SERDES_NONCU_MASTER idle */
 		gfx_v8_0_wait_for_rlc_serdes(adev);
 
-		/* 4 - write cmd to set CGLS */
+		/* 3 - write cmd to set CGLS */
 		gfx_v8_0_send_serdes_cmd(adev, BPM_REG_CGLS_EN, SET_BPM_SERDES_CMD);
 
-		/* 5 - enable cgcg */
+		/* 4 - enable cgcg */
 		data |= RLC_CGCG_CGLS_CTRL__CGCG_EN_MASK;
 
 		if (adev->cg_flags & AMD_CG_SUPPORT_GFX_CGLS) {
@@ -5775,6 +5770,11 @@ static void gfx_v8_0_update_coarse_grain
 
 		if (temp != data)
 			WREG32(mmRLC_CGCG_CGLS_CTRL, data);
+
+		/* 5 enable cntx_empty_int_enable/cntx_busy_int_enable/
+		 * Cmp_busy/GFX_Idle interrupts
+		 */
+		gfx_v8_0_enable_gui_idle_interrupt(adev, true);
 	} else {
 		/* disable cntx_empty_int_enable & GFX Idle interrupt */
 		gfx_v8_0_enable_gui_idle_interrupt(adev, false);