On Monday, August 02, 2010, Hidetoshi Seto wrote: > (2010/07/31 7:32), Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > PCIe port service drivers ask the BIOS, through _OSC, for control of > > the services they handle. Unfortunately, each of them individually > > asks for control of the PCIe capability structure and if that is > > granted, some BIOSes expect that the other PCIe port services will be > > configured and handled by the kernel as well. If that is not the > > case (eg. one of the PCIe port service drivers is not loaded), the > > BIOS may be confused and may cause the system as a whole to misbehave > > (eg. on one of such systems enabling the native PCIe PME service > > without loading the native PCIe hot-plug service driver causes a > > storm of ACPI notify requests to appear). > > > > For this reason rework the PCIe port driver so that (1) it checks > > which native PCIe port services can be enabled, according to the > > BIOS, and (2) it requests control of all these services > > simultaneously. In particular, this causes pcie_portdrv_probe() to > > fail if the BIOS refuses to grant control of the PCIe capability > > structure, which means that no native PCIe port services can be > > enabled for the PCIe root complex the given port belongs to. > > > > Make it possible to override this behavior using a new command line > > switch pcie_ports= that can be set to 'auto' (ask the BIOS, the > > default), 'native' (use the PCIe native services regardless of the > > BIOS response to the control request), or 'compat' (do not use the > > PCIe native services at all). > > > > Accordingly, rework the existing PCIe port service drivers so that > > they don't request control of the services directly. > > > > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> > > --- > > It seems that this patch still have more than one logical changes. > > I think that "pcie_ports=compat" has an independent function, so > it could be in a separated patch. > > Maybe we can have 2 patches (at least) before this change: > [1] aerdrv: introduce pci_aer_available() > [2] portdrv: introduce pcie_ports= > 'compat' to disable all port services > [3] (this patch) I can do that, but I'm not sure if that really is going to make things better. The introduction of pcie_ports=, for example, is only necessary because of the other changes in the $subject patch, so why do you want it to be separate? Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
