[PATCH 2/3] drm/amd/pm/smu11: poll BACO status after RPM BACO exits

[Guchun Chen]

After executing BACO exit, driver needs to poll the status
to ensure FW has completed BACO exit sequence to prevent
timing issue.

v2: use usleep_range to replace msleep to fix checkpatch.pl warnings

Signed-off-by: Guchun Chen <guchun.chen at amd.com>
---
 .../gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c    | 24 ++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
index ad5f6a15a1d7..ad66d57aa102 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
@@ -79,6 +79,17 @@ MODULE_FIRMWARE("amdgpu/beige_goby_smc.bin");
 #define mmTHM_BACO_CNTL_ARCT			0xA7
 #define mmTHM_BACO_CNTL_ARCT_BASE_IDX		0
 
+static void smu_v11_0_poll_baco_exit(struct smu_context *smu)
+{
+	struct amdgpu_device *adev = smu->adev;
+	uint32_t data, loop = 0;
+
+	do {
+		usleep_range(1000, 1100);
+		data = RREG32_SOC15(THM, 0, mmTHM_BACO_CNTL);
+	} while ((data & 0x100) && (++loop < 100));
+}
+
 int smu_v11_0_init_microcode(struct smu_context *smu)
 {
 	struct amdgpu_device *adev = smu->adev;
@@ -1689,7 +1700,18 @@ int smu_v11_0_baco_enter(struct smu_context *smu)
 
 int smu_v11_0_baco_exit(struct smu_context *smu)
 {
-	return smu_v11_0_baco_set_state(smu, SMU_BACO_STATE_EXIT);
+	int ret;
+
+	ret = smu_v11_0_baco_set_state(smu, SMU_BACO_STATE_EXIT);
+	if (!ret) {
+		/*
+		 * Poll BACO exit status to ensure FW has completed
+		 * BACO exit process to avoid timing issues.
+		 */
+		smu_v11_0_poll_baco_exit(smu);
+	}
+
+	return ret;
 }
 
 int smu_v11_0_mode1_reset(struct smu_context *smu)
-- 
2.25.1