On Thu, 2010-09-02 at 10:31 +0800, Jin Dongming wrote: > acpi_pre_map() is used for remapping the physical address of I/O, so > it should be return NULL or remapped virtual address. The problem is > that when (paddr - pg_off) equals 0, no matter whether I/O remapping is > successful or not, the function returns NULL. > > In acpi_pre_map(), after the physical address is remapped sucessfully, > it will check whether the physical address has been added into acpi_iomaps > list again. > - If the physical address has beed added into acpi_iomaps, the virtual > address will be saved in vaddr. > - Otherwise, NULL be saved in vaddr. > > So if the physical address is the first time to be remapped, vaddr will be > NULL always. > > In many cases, (paddr - pg_off) may not equal 0. So the function could work > well. In our machine, (paddr - pg_off) equals 0, so the return value of > acpi_pre_map() is NULL. > > This patch fixed it and I confirmed it on x86_64 next-tree. > > Signed-off-by: Jin Dongming <jin.dongming@xxxxxxxxxxxxxxxxxx> Acked-by: Huang Ying <ying.huang@xxxxxxxxx> Best Regards, Huang Ying -- 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
