[PATCH v4 1/6] media: iris: wait for vpu NoC to enter low power during power off

[Vikash Garodia]

The recommended hardware sequence requires software to wait for vpu NoC
to enter in low power mode and then deassert the low power idle (LPI)
control. Add the missing LPI status poll and move the LPI control
deassertion after the hardware acks LPI mode. This avoids any pending
transactions on vpu NoC before shutting it down.

Fixes: dde659d37036 ("media: iris: Introduce vpu ops for vpu4 with necessary hooks")
Cc: stable@xxxxxxxxxxxxxxx
Co-developed-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
Signed-off-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
 drivers/media/platform/qcom/iris/iris_vpu4x.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/qcom/iris/iris_vpu4x.c b/drivers/media/platform/qcom/iris/iris_vpu4x.c
index 02e100a4045fced33d7a3545b632cc5f0955233f..32a161c8d534a34eee4e7778426b4947b6c17003 100644
--- a/drivers/media/platform/qcom/iris/iris_vpu4x.c
+++ b/drivers/media/platform/qcom/iris/iris_vpu4x.c
@@ -316,6 +316,10 @@ static void iris_vpu4x_power_off_hardware(struct iris_core *core)
 	if (!handshake_done && handshake_busy)
 		dev_err(core->dev, "LPI handshake timeout\n");
 
+	readl_poll_timeout(core->reg_base + AON_WRAPPER_MVP_NOC_LPI_STATUS,
+			   value, value & BIT(0), 200, 2000);
+	writel(0x0, core->reg_base + AON_WRAPPER_MVP_NOC_LPI_CONTROL);
+
 	writel(MVP_NOC_RESET_REQ_MASK, core->reg_base + AON_WRAPPER_MVP_NOC_RESET_REQ);
 	ret = readl_poll_timeout(core->reg_base + AON_WRAPPER_MVP_NOC_RESET_ACK,
 				 value, value & MVP_NOC_RESET_REQ_MASK, 200, 2000);

-- 
2.34.1