mirror of https://gitee.com/openkylin/linux.git
b51306c634
During test of one IB card with guest VM, found that, msi is not
initialized properly.
It turns out __write_msi_msg will do nothing if device current_state is
not PCI_D0. And, that pci device does not have pm_cap in guest VM.
There is an error in setting of power state to PCI_D0 in
pci_enable_device(), but error is not returned for this. Following is
code flow:
pci_enable_device() --> __pci_enable_device_flags() -->
do_pci_enable_device() --> pci_set_power_state() -->
__pci_start_power_transition()
We have following condition inside __pci_start_power_transition():
if (platform_pci_power_manageable(dev)) {
error = platform_pci_set_power_state(dev, state);
if (!error)
pci_update_current_state(dev, state);
} else {
error = -ENODEV;
/* Fall back to PCI_D0 if native PM is not supported */
if (!dev->pm_cap)
dev->current_state = PCI_D0;
}
Here, from platform_pci_set_power_state(), acpi_pci_set_power_state() is
getting called and that is failing with ENODEV because of following
condition:
if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0",&tmp)))
return -ENODEV;
Because of that, pci_update_current_state() is not getting called.
With this patch, if device power state can not be set via
platform_pci_set_power_state and that device does not have native pm
support, then PCI device power state will be set to PCI_D0.
-v2: This also reverts
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|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| acpi_pcihp.c | ||
| acpiphp.h | ||
| acpiphp_core.c | ||
| acpiphp_glue.c | ||
| acpiphp_ibm.c | ||
| cpci_hotplug.h | ||
| cpci_hotplug_core.c | ||
| cpci_hotplug_pci.c | ||
| cpcihp_generic.c | ||
| cpcihp_zt5550.c | ||
| cpcihp_zt5550.h | ||
| cpqphp.h | ||
| cpqphp_core.c | ||
| cpqphp_ctrl.c | ||
| cpqphp_nvram.c | ||
| cpqphp_nvram.h | ||
| cpqphp_pci.c | ||
| cpqphp_sysfs.c | ||
| fakephp.c | ||
| ibmphp.h | ||
| ibmphp_core.c | ||
| ibmphp_ebda.c | ||
| ibmphp_hpc.c | ||
| ibmphp_pci.c | ||
| ibmphp_res.c | ||
| pci_hotplug_core.c | ||
| pciehp.h | ||
| pciehp_acpi.c | ||
| pciehp_core.c | ||
| pciehp_ctrl.c | ||
| pciehp_hpc.c | ||
| pciehp_pci.c | ||
| pcihp_skeleton.c | ||
| pcihp_slot.c | ||
| rpadlpar.h | ||
| rpadlpar_core.c | ||
| rpadlpar_sysfs.c | ||
| rpaphp.h | ||
| rpaphp_core.c | ||
| rpaphp_pci.c | ||
| rpaphp_slot.c | ||
| sgi_hotplug.c | ||
| shpchp.h | ||
| shpchp_core.c | ||
| shpchp_ctrl.c | ||
| shpchp_hpc.c | ||
| shpchp_pci.c | ||
| shpchp_sysfs.c | ||