Hi Yinghai, On 18 April 2017 at 05:45, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > On Mon, Apr 17, 2017 at 2:36 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >> From: Yongji Xie <elohimes@xxxxxxxxx> >> >> In case that one device's alignment is greater than its size, >> we may get an incorrect size and alignment for its bus's memory >> window in pbus_size_mem(). This patch fixes this case. > > In which case, that device alignment is not same as size? > or powerpc need small size, but alignment is PAGE_SIZE? > Yes, powerpc may have some small size (smaller than PAGE_SIZE) devices whose alignment would be enforced to be PAGE_SIZE by pcibios_default_alignment() (in patch 4). Thanks, Yongji