[PATCH] drm/amdgpu: fix reload KMD hang on GFX10 KIQ

[Deng, Emily]

[AMD Official Use Only - Internal Distribution Only]

Reviewed-by: Emily Deng <Emily.Deng at amd.com>

>-----Original Message-----
>From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Monk
>Liu
>Sent: Monday, August 10, 2020 11:59 AM
>To: amd-gfx at lists.freedesktop.org
>Cc: Liu, Monk <Monk.Liu at amd.com>
>Subject: [PATCH] drm/amdgpu: fix reload KMD hang on GFX10 KIQ
>
>GFX10 KIQ will hang if we try below steps:
>modprobe amdgpu
>rmmod amdgpu
>modprobe amdgpu sched_hw_submission=4
>
>Due to KIQ is always living there even after KMD unloaded thus when doing the
>realod KIQ will crash upon its register being programed by different values with
>the previous loading (the config like HQD addr, ring size, is easily changed if we
>alter the sched_hw_submission)
>
>the fix is we must inactive KIQ first before touching any of its registgers
>
>Signed-off-by: Monk Liu <Monk.Liu at amd.com>
>---
> drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>index 622f442..0702c94 100644
>--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>@@ -6435,6 +6435,10 @@ static int gfx_v10_0_kiq_init_register(struct
>amdgpu_ring *ring)
> struct v10_compute_mqd *mqd = ring->mqd_ptr;
> int j;
>
>+/* inactivate the queue */
>+if (amdgpu_sriov_vf(adev))
>+WREG32_SOC15(GC, 0, mmCP_HQD_ACTIVE, 0);
>+
> /* disable wptr polling */
> WREG32_FIELD15(GC, 0, CP_PQ_WPTR_POLL_CNTL, EN, 0);
>
>--
>2.7.4
>
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