[PATCH 5/7] drm/amdgpu/uvd3.1: Don't validate the firmware when already validated

["Timur Kristóf" <timur.kristof@gmail.com>]

UVD 3.1 firmware validation seems to always fail after
attempting it when it had already been validated.
(This works similarly with the VCE 1.0 as well.)

Don't attempt repeating the validation when it's already done.

This caused issues in situations when the system isn't able
to suspend the GPU properly and so the GPU isn't actually
powered down. Then amdgpu would fail when calling the IP
block resume function.

Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/2887
Fixes: bb7978111dd3 ("drm/amdgpu: fix SI UVD firmware validate resume fail")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/uvd_v3_1.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/uvd_v3_1.c b/drivers/gpu/drm/amd/amdgpu/uvd_v3_1.c
index fea576a7f397f..efb3fde919ee3 100644
--- a/drivers/gpu/drm/amd/amdgpu/uvd_v3_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/uvd_v3_1.c
@@ -242,6 +242,10 @@ static void uvd_v3_1_mc_resume(struct amdgpu_device *adev)
 	uint64_t addr;
 	uint32_t size;
 
+	/* When the keyselect is already set, don't perturb it. */
+	if (RREG32(mmUVD_FW_START))
+		return;
+
 	/* program the VCPU memory controller bits 0-27 */
 	addr = (adev->uvd.inst->gpu_addr + AMDGPU_UVD_FIRMWARE_OFFSET) >> 3;
 	size = AMDGPU_UVD_FIRMWARE_SIZE(adev) >> 3;
@@ -284,6 +288,12 @@ static int uvd_v3_1_fw_validate(struct amdgpu_device *adev)
 	int i;
 	uint32_t keysel = adev->uvd.keyselect;
 
+	if (RREG32(mmUVD_FW_START) & UVD_FW_STATUS__PASS_MASK) {
+		dev_dbg(adev->dev, "UVD keyselect already set: 0x%x (on CPU: 0x%x)\n",
+			RREG32(mmUVD_FW_START), adev->uvd.keyselect);
+		return 0;
+	}
+
 	WREG32(mmUVD_FW_START, keysel);
 
 	for (i = 0; i < 10; ++i) {
-- 
2.53.0