Commit 95e1b60f authored by Shyam Sundar S K's avatar Shyam Sundar S K Committed by Hans de Goede
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platform/x86: amd-pmc: Fix command completion code 



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.

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.

Also, add a mutex to protect amd_pmc_send_cmd() calls to SMU.

Fixes: 156ec473 ("platform/x86: amd-pmc: Add AMD platform support for S2Idle")
Signed-off-by: default avatarShyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: default avatarRaul E Rangel <rrangel@chromium.org>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210629084803.248498-2-Shyam-sundar.S-k@amd.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 95d42920

drivers/platform/x86/amd-pmc.c

+36 −2
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ struct amd_pmc_dev { 
	u32 base_addr;

	u32 cpu_id;

	struct device *dev;

	struct mutex lock; /* generic mutex lock */

#if IS_ENABLED(CONFIG_DEBUG_FS)

	struct dentry *dbgfs_dir;

#endif /* CONFIG_DEBUG_FS */
@@ -138,9 +139,10 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set) 
	u8 msg;

	u32 val;



	mutex_lock(&dev->lock);

	/* 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 != 0, 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");
@@ -156,7 +158,37 @@ 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);

	return 0;

	/* 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,

				PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);

	if (rc) {

		dev_err(dev->dev, "SMU response timed out\n");

		goto out_unlock;

	}



	switch (val) {

	case AMD_PMC_RESULT_OK:

		break;

	case AMD_PMC_RESULT_CMD_REJECT_BUSY:

		dev_err(dev->dev, "SMU not ready. err: 0x%x\n", val);

		rc = -EBUSY;

		goto out_unlock;

	case AMD_PMC_RESULT_CMD_UNKNOWN:

		dev_err(dev->dev, "SMU cmd unknown. err: 0x%x\n", val);

		rc = -EINVAL;

		goto out_unlock;

	case AMD_PMC_RESULT_CMD_REJECT_PREREQ:

	case AMD_PMC_RESULT_FAILED:

	default:

		dev_err(dev->dev, "SMU cmd failed. err: 0x%x\n", val);

		rc = -EIO;

		goto out_unlock;

	}



out_unlock:

	mutex_unlock(&dev->lock);

	return rc;

}



static int __maybe_unused amd_pmc_suspend(struct device *dev)
@@ -259,6 +291,7 @@ static int amd_pmc_probe(struct platform_device *pdev) 


	amd_pmc_dump_registers(dev);



	mutex_init(&dev->lock);

	platform_set_drvdata(pdev, dev);

	amd_pmc_dbgfs_register(dev);

	return 0;
@@ -269,6 +302,7 @@ static int amd_pmc_remove(struct platform_device *pdev) 
	struct amd_pmc_dev *dev = platform_get_drvdata(pdev);



	amd_pmc_dbgfs_unregister(dev);

	mutex_destroy(&dev->lock);

	return 0;

}