提交 3cde8e7a 编写于 作者: R Rafael J. Wysocki 提交者: Zheng Zengkai

PCI: Use pci_update_current_state() in pci_enable_device_flags()

stable inclusion
from stable-5.10.67
commit cc12ab5951aa3a9d0893614120560179db8659a2
bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cc12ab5951aa3a9d0893614120560179db8659a2

--------------------------------

[ Upstream commit 14858dcc ]

Updating the current_state field of struct pci_dev the way it is done
in pci_enable_device_flags() before calling do_pci_enable_device() may
not work.  For example, if the given PCI device depends on an ACPI
power resource whose _STA method initially returns 0 ("off"), but the
config space of the PCI device is accessible and the power state
retrieved from the PCI_PM_CTRL register is D0, the current_state
field in the struct pci_dev representing that device will get out of
sync with the power.state of its ACPI companion object and that will
lead to power management issues going forward.

To avoid such issues, make pci_enable_device_flags() call
pci_update_current_state() which takes ACPI device power management
into account, if present, to retrieve the current power state of the
device.

Link: https://lore.kernel.org/lkml/20210314000439.3138941-1-luzmaximilian@gmail.com/Reported-by: NMaximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMaximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
上级 06715960
...@@ -1880,11 +1880,7 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) ...@@ -1880,11 +1880,7 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
* so that things like MSI message writing will behave as expected * so that things like MSI message writing will behave as expected
* (e.g. if the device really is in D0 at enable time). * (e.g. if the device really is in D0 at enable time).
*/ */
if (dev->pm_cap) { pci_update_current_state(dev, dev->current_state);
u16 pmcsr;
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
}
if (atomic_inc_return(&dev->enable_cnt) > 1) if (atomic_inc_return(&dev->enable_cnt) > 1)
return 0; /* already enabled */ return 0; /* already enabled */
......
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