[PATCH v2 1/7] platform/x86: amd-pmc: Fix command completion code

[Shyam Sundar S K <Shyam-sundar.S-k@amd.com>]

The protocol to submit a job request to SMU is to wait for
AMD_PMC_REGISTER_RESPONSE to return 1,meaning SMU is ready to take
requests. PMC driver has to make sure that the response code is always
AMD_PMC_RESULT_OK before making any command submissions.

Also, when we submit a message to SMU, we have to wait until it processes
the request. Adding a read_poll_timeout() check as this was missing in
the existing code.

Fixes: 156ec4731cb2 ("platform/x86: amd-pmc: Add AMD platform support for S2Idle")
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
---
v2: no change

 drivers/platform/x86/amd-pmc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
index b9da58ee9b1e..9c8a53120767 100644
--- a/drivers/platform/x86/amd-pmc.c
+++ b/drivers/platform/x86/amd-pmc.c
@@ -140,7 +140,7 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set)
 
 	/* Wait until we get a valid response */
 	rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMC_REGISTER_RESPONSE,
-				val, val > 0, PMC_MSG_DELAY_MIN_US,
+				val, val == AMD_PMC_RESULT_OK, PMC_MSG_DELAY_MIN_US,
 				PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
 	if (rc) {
 		dev_err(dev->dev, "failed to talk to SMU\n");
@@ -156,6 +156,14 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set)
 	/* Write message ID to message ID register */
 	msg = (dev->cpu_id == AMD_CPU_ID_RN) ? MSG_OS_HINT_RN : MSG_OS_HINT_PCO;
 	amd_pmc_reg_write(dev, AMD_PMC_REGISTER_MESSAGE, msg);
+	/* Wait until we get a valid response */
+	rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMC_REGISTER_RESPONSE,
+				val, val == AMD_PMC_RESULT_OK, PMC_MSG_DELAY_MIN_US,
+				PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
+	if (rc) {
+		dev_err(dev->dev, "SMU response timed out\n");
+		return rc;
+	}
 	return 0;
 }
 
-- 
2.25.1