On Monday 19 December 2005 12:24, Johannes Stezenbach wrote: > On Mon, Dec 19, 2005, Hans Verkuil wrote: > > OK, after receiving some comments about my fix in saa7146_hlp.c I'm > > submitting it again (and this time to the list first, my apologies > > for not doing that before) and this time with the comment I should > > have added in the first place. > > > > I didn't just hide a warning, I actually thought about it :-) > > ;-) > > > + /* The base pointer is a 32-bit pointer into DMA memory. > > + The unsigned long cast is to remove a 64-bit compile warning > > since + it looks like a 64-bit address is cast to a 32-bit > > value. */ + u32 base = (u32)(unsigned long)vv->ov_fb.base; > > For me at least, this needs more explanation. Why are these pointers > 32bit even on a 64bit machine? > > If they are PCI addresses, then I believe there are machines who have > the bus not mapped at address zero but at some offset, so you need > 64 bits to represent a 32bit PCI address. (Also, shouldn't this be > dma_addr_t in this case? What type does vv->ov_fb.base have?) > > If if is just an offset then the name is wrong. > > Will this value be set in a 32bit chip register?
