On Thu, Oct 29, 2020 at 10:57 AM Shyam Sundar S K
<Shyam-sundar.S-k@xxxxxxx> wrote:
>
> AMD Power Management Controller driver aka. amd-pmc driver is the
aka. -> a.k.a. or AKA
> controller which is meant for final S2Idle transaction that goes to the
for the final
> PMFW running on the AMD SMU (System Management Unit) responsible for
> tuning of the VDD.
>
> Once all the monitored list or the idle constraints are met, this driver
> would go and set the OS_HINT (meaning all the devices have reached to
> their lowest state possible) via the SMU mailboxes.
>
> This driver would also provide some debug capabilities via debugfs.
...
> +F: drivers/platform/x86/amd-pmc.c
> +F: drivers/platform/x86/amd-pmc.h
Can be one entry.
...
> + help
> + The driver provides support for AMD Power Management Controller
> + primarily responsible for S2Idle transactions that are driven from
> + a platform firmware running on SMU. This driver also provides debug
a debug
> + mechanism to investigate the S2Idle transactions and failures.
How will the module be called?
...
> +static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
> +{
> + struct dentry *dir;
What is the point of having the temporary variable?
> + dir = debugfs_create_dir("amd_pmc", NULL);
> + dev->dbgfs_dir = dir;
> + debugfs_create_file("smu_fw_info", 0644, dir, dev, &smu_fw_info_fops);
> +}
...
> +static int amd_pmc_poll_smu_response(struct amd_pmc_dev *dev)
> +{
> + int rc = 0, index;
Redundant assignment.
> + for (index = 0; index < RESPONSE_REGISTER_LOOP_MAX; index++) {
> + rc = amd_pmc_reg_read(dev, AMD_PMC_REGISTER_RESPONSE);
> + if (rc != 0)
> + break;
if (rc)
return rc;
> +
> + usleep_range(PMC_MSG_DELAY_MIN, PMC_MSG_DELAY_MAX);
> + }
> +
> + return rc;
> +}
Seems like home grown readx_poll_timeout().
...
> + int rc = 0;
Redundant assignment.
...
> + /* Wait until the response register is non-zero */
This comment is confusing.
I guess you rather need to return an error code from the called function...
> + rc = amd_pmc_poll_smu_response(dev);
> + if (!rc) {
> + dev_err(dev->dev, "failed to talk to SMU\n");
> + return -EIO;
...and propagate it here.
> + }
...
> + if (arg) {
> + /* Wait until the response register is non-zero */
> + rc = amd_pmc_poll_smu_response(dev);
> + if (!rc) {
As above. This is an unusual pattern in the kernel.
> + dev_err(dev->dev, "failed to talk to SMU\n");
> + return -EIO;
> + }
> + /* If message register is OK, then SMU has finished processing
> + * the message, and then read back from AMD_PMC_REGISTER_ARGUMENT
> + */
Comment style!
> + rc = amd_pmc_reg_read(dev, AMD_PMC_REGISTER_ARGUMENT);
And where is rc going?
> + }
> +
> + return 0;
...
> +#ifdef CONFIG_PM_SLEEP
__maybe_unused is slightly better.
...
> +static int amd_pmc_suspend(struct device *dev)
> +{
> + struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
> + int rc = 0;
What is the point?
> + rc = amd_pmc_send_cmd(pdev, 1, 0);
> + if (rc)
> + dev_err(pdev->dev, "suspend failed\n");
> +
> + amd_pmc_dump_registers(pdev);
> +
> + return 0;
> +}
> +
> +static int amd_pmc_resume(struct device *dev)
> +{
> + struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
> + int rc = 0;
Ditto.
> + rc = amd_pmc_send_cmd(pdev, 0, 0);
> + if (rc)
> + dev_err(pdev->dev, "resume failed\n");
> +
> + amd_pmc_dump_registers(pdev);
> +
> + return 0;
> +}
> +#endif
...
> + rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
> + if (!rdev || (!(rdev->vendor == PCI_VENDOR_ID_AMD) &&
> + (rdev->device == AMD_CPU_ID_PCO ||
> + rdev->device == AMD_CPU_ID_RN))) {
> + return -ENODEV;
> + }
Can you rather create an additional PCI ID table and simple use pci_match_id()?
> + err = pci_write_config_dword(rdev, AMD_PMC_SMU_INDEX_ADDRESS, AMD_PMC_BASE_ADDR_LO);
> + if (err) {
> + dev_err(dev->dev, "error writing to 0x%x\n", AMD_PMC_SMU_INDEX_ADDRESS);
> + return err;
> + }
Returning positive error codes?!
...
> + dev->smu_base = ioremap(base_addr, AMD_PMC_MAPPING_SIZE);
devm_ioremap()?
> + if (!dev->smu_base)
> + return -ENOMEM;
> +
> + dev->regbase = ioremap(base_addr + AMD_PMC_BASE_ADDR_OFFSET, AMD_PMC_MAPPING_SIZE);
Ditto.
> + if (!dev->regbase) {
> + iounmap(dev->smu_base);
> + return -ENOMEM;
> + }
...
> + .acpi_match_table = ACPI_PTR(amd_pmc_acpi_ids),
It depends on ACPI. What is the point of ACPI_PTR?
...
> +
Redundant blank line
> +module_platform_driver(amd_pmc_driver);
...
> +++ b/drivers/platform/x86/amd-pmc.h
Who is going to use this file?
...
> +#define AMD_PMC_BASE_ADDR_HI_MASK 0xFFF00000L
> +#define AMD_PMC_BASE_ADDR_LO_MASK 0x0000FFFFL
You included bits.h and not using it, why?
...
> +#define PMC_MSG_DELAY_MIN 100
> +#define PMC_MSG_DELAY_MAX 200
Units?
...
> +enum amd_pmc_def {
> + msg_test = 0x01,
> + msg_os_hint_pco,
> + msg_os_hint_rn,
> +};
Hmm... Perhaps capital letters?
--
With Best Regards,
Andy Shevchenko
