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@xxxxxxx> --- 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