it' s not in ISA space. once loading the NVIDIA driver, the warnign oops shows up. 4K starting at 0x9f800 (i.e. to 0xa007ff) overlap with the ISA space (starting at 0xa0000). When I don' t load the driver, no oops. So I am assuming nvidia driver request 4K of memory, that happens to be available in the bios area. I think that there is a check missing somewhere to report that available RAM buffer is already reserved (by BIOS) so we need to get it from somewhere else. Does it make sense? -Mathieu On Wed, May 19, 2010 at 4:00 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: > On 05/19/2010 03:58 PM, Mathieu Rondonneau wrote: >> Thanks for the feedback. >> >> No, I don' t see any changes in the /proc/iomem. >> >> I am trying to prevent a ioremap of a 4K size on a non aligned 4K >> address that is below the ISA_START_ADDRESS. >> >> The problem generates a oops about overlapping. >> I have a fix which instruct to not to do any re-map if the section >> name is "reserved". >> Which is not really clean. >> I am looking for a clean way to tell the ioremap function to not remap >> bios reserved memory. >> That' s why I thought the e820 would be a good start. >> >> I will continue looking into this. It does not crash the systems. A >> warning generates the oops. >> > > Why are you mapping a fixed-address in ISA space to begin with? > > Requests to a fixed address (as opposed to dynamic allocation) have to > be granted even in reserved space -- after all, that's what the address > might be reserved for! > > -hpa > -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html