From ad97d9de45835b6a0f71983b0ae0cffd7306730a Mon Sep 17 00:00:00 2001
From: shaoyunl <shaoyun.liu@amd.com>
Date: Thu, 22 Nov 2018 11:45:24 -0500
Subject: drm/amdgpu: Add delay after enable RLC ucode
Git-commit: ad97d9de45835b6a0f71983b0ae0cffd7306730a
Patch-mainline: v4.20-rc5
References: bsc#1113956
Driver shouldn't try to access any GFX registers until RLC is idle.
During the test, it took 12 seconds for RLC to clear the BUSY bit
in RLC_GPM_STAT register which is un-acceptable for driver.
As per RLC engineer, it would take RLC Ucode less than 10,000 GFXCLK
cycles to finish its critical section. In a lowest 300M enginer clock
setting(default from vbios), 50 us delay is enough.
This commit fix the hang when RLC introduce the work around for XGMI
which requires more cycles to setup more registers than normal
Signed-off-by: shaoyunl <shaoyun.liu@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 6d7baf59d6e1..21363b2b2ee5 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2440,12 +2440,13 @@ static void gfx_v9_0_rlc_start(struct amdgpu_device *adev)
#endif
WREG32_FIELD15(GC, 0, RLC_CNTL, RLC_ENABLE_F32, 1);
+ udelay(50);
/* carrizo do enable cp interrupt after cp inited */
- if (!(adev->flags & AMD_IS_APU))
+ if (!(adev->flags & AMD_IS_APU)) {
gfx_v9_0_enable_gui_idle_interrupt(adev, true);
-
- udelay(50);
+ udelay(50);
+ }
#ifdef AMDGPU_RLC_DEBUG_RETRY
/* RLC_GPM_GENERAL_6 : RLC Ucode version */
--
2.20.1