On Tue, Jun 24, 2008 at 7:49 PM, Zhao Yakui <yakui.zhao@xxxxxxxxx> wrote: > On Tue, 2008-06-24 at 11:48 -0700, Alok Kataria wrote: >> Evaluates the _CRS object under PCI0 looking for producer resources. >> Then searches the e820 memory space for a gap within these producer resources. >> >> Allows us to find a gap for the unclaimed pci resources or MMIO resources >> for hotplug devices within the BIOS allowed pci regions. >> > It seems reasonable. > But if the resource obtained from the PCI0 _CRS method is incorrect, we > will get the incorrect pci_mem_start. Hi Yakui, What do you mean by the PCI0 _CRS being incorrect ? Why would the BIOS give a incorrect _CRS object ? Also we don't just take the value given from the _CRS method, we still read the e820_map to search for an unallocated resource. So even if (by chance) the _CRS method returns incorrect value we would still figure out if there is a collision with an already allocated resource. > > At the same time after the patch is applied, pci_mem_start will be > parsed in two different ways. Yes pci_mem_start would be initialized in 2 different ways but we still have to parse the e820_map the old way because there could be systems without ACPI. > If the result is different, maybe the > incorrect pci_mem_start will be used. Yeah, The result is different in my case. Though my BIOS reserves hotpluggable memory region, kernel doesn't respect that right now and just parses the e820_map to calculate the gap and pci_mem_start value. I have explained the problem in this mail. http://marc.info/?l=linux-acpi&m=121391675711763&w=2 Maybe nobody has seen this problem yet, because there are no systems out there with less than 4GB memory to start with and which allow memory hotplug. But still i don't understand what do you mean by, we can get incorrect pci_mem_start, in which case ? Thanks, Alok > > Best regards. > Yakui >> >> >> -- >> 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- 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
