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由 Rafael J. Wysocki 提交于
There is the assumption in acpi_pci_osc_control_set() that it is always sufficient to compare the mask of _OSC control bits to be requested with the result of an _OSC query where all of the known control bits have been checked. However, in general, that need not be the case. For example, if an _OSC feature A depends on an _OSC feature B and control of A, B plus another _OSC feature C is requested simultaneously, the BIOS may return A, B, C, while it would only return C if A and C were requested without B. That may result in passing a wrong mask of _OSC control bits to an _OSC control request, in which case the BIOS may only grant control of a subset of the requested features. Moreover, acpi_pci_run_osc() will return error code if that happens and the caller of acpi_pci_osc_control_set() will not know that it's been granted control of some _OSC features. Consequently, the system will generally not work as expected. Apart from this acpi_pci_osc_control_set() always uses the mask of _OSC control bits returned by the very first invocation of acpi_pci_query_osc(), but that is done with the second argument equal to OSC_PCI_SEGMENT_GROUPS_SUPPORT which generally happens to affect the returned _OSC control bits. For these reasons, make acpi_pci_osc_control_set() always check if control of the requested _OSC features will be granted before making the final control request. As a result, the osc_control_qry and osc_queried members of struct acpi_pci_root are not necessary any more, so drop them and remove the remaining code referring to them. Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl> Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
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