On Thu, Apr 12, 2012 at 4:22 AM, Steven Newbury <steve at snewbury.org.uk> wrote: > Thanks, that fixed it! :) I had a similar patch I've been working on but I > had my fix in the wrong place! > > In the working case, initially the BIOS has set GMA to within the low system > DRAM 0xC0000000 obviously invalid. ?This conflict is detected and it's > relallocated to 0x12000000. > > I've attempted to modify probe.c to disable 64-bit BARs not allocated above > 4G so they get reallocated above when possible later. ?It seemed to work, but > again broke GMA despite the BAR originally containing an invalid address as > mentioned above, it seems for some reason something is different when the > conflict is detected and rellocated, compared to disabling it early then > allocating a valid value..? > > It would be useful to preserve as much low PCI memory address space as > possible for hotplug devices (like my Radeon), but the other problem is small > regions get allocated at the bottom, resulting in the inability to find large > aligned regions later on. ?I see code to default to top-down allocation was > reverted, I guess I'm going to have to dig into the archive to find out why...
for hotplug case, You can work around like: after hotplug add, 1. use lspci and /proc/iomem to find out offending device and bridge. 2. use /sys/.../unbind etc to stop driver for those devices. 3. use setpci to clear related BAR 4. use /sys/devices/pci000..../remove to remove those devices 5. echo 1 > /sys/bus/pci/rescan then it should work... Yinghai
