Hi Alex, On 4/30/21 1:39 PM, Alex Williamson wrote: > External email: Use caution opening links or attachments > > > On Wed, 28 Apr 2021 19:49:06 -0500 > Shanker Donthineni <sdonthineni@xxxxxxxxxx> wrote: > >> The _RST is a standard method specified in the ACPI specification. It >> provides a function level reset when it is described in the acpi_device >> context associated with PCI-device. >> >> Implement a new reset function pci_dev_acpi_reset() for probing RST >> method and execute if it is defined in the firmware. The ACPI binding >> information is available only after calling device_add(), so move >> pci_init_reset_methods() to end of the pci_device_add(). >> >> The default priority of the acpi reset is set to below device-specific >> and above hardware resets. >> >> Signed-off-by: Shanker Donthineni <sdonthineni@xxxxxxxxxx> >> --- >> changes since v2: >> - fix typo in the commit text >> changes since v2: >> - rebase patch on top of https://lore.kernel.org/linux-pci/20210409192324.30080-1-ameynarkhede03@xxxxxxxxx/ >> >> drivers/pci/pci.c | 30 ++++++++++++++++++++++++++++++ >> drivers/pci/probe.c | 2 +- >> include/linux/pci.h | 2 +- >> 3 files changed, 32 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 664cf2d358d6..510f9224a3b0 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -5076,6 +5076,35 @@ static void pci_dev_restore(struct pci_dev *dev) >> err_handler->reset_done(dev); >> } >> >> +/** >> + * pci_dev_acpi_reset - do a function level reset using _RST method >> + * @dev: device to reset >> + * @probe: check if _RST method is included in the acpi_device context. >> + */ >> +static int pci_dev_acpi_reset(struct pci_dev *dev, int probe) >> +{ >> +#ifdef CONFIG_ACPI >> + acpi_handle handle = ACPI_HANDLE(&dev->dev); >> + >> + /* Return -ENOTTY if _RST method is not included in the dev context */ >> + if (!handle || !acpi_has_method(handle, "_RST")) >> + return -ENOTTY; >> + >> + /* Return 0 for probe phase indicating that we can reset this device */ >> + if (probe) >> + return 0; >> + >> + /* Invoke _RST() method to perform a function level reset */ >> + if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) { >> + pci_warn(dev, "Failed to reset the device\n"); >> + return -EINVAL; >> + } >> + return 0; >> +#else >> + return -ENOTTY; >> +#endif >> +} >> + >> /* >> * The ordering for functions in pci_reset_fn_methods >> * is required for reset_methods byte array defined >> @@ -5083,6 +5112,7 @@ static void pci_dev_restore(struct pci_dev *dev) >> */ >> const struct pci_reset_fn_method pci_reset_fn_methods[] = { >> { .reset_fn = &pci_dev_specific_reset, .name = "device_specific" }, >> + { .reset_fn = &pci_dev_acpi_reset, .name = "acpi_reset" }, > Would it make sense to name this "acpi_rst" after the method name? > Otherwise "_reset" is a bit redundant to the sysfs attribute, we could > simply name it "acpi" to indicate an ACPI based reset. Thanks, > Thanks, I will change to "{ .reset_fn = &pci_dev_acpi_reset, .name = "acpi" }"
