On Wed, Apr 07, 2010 at 11:55:19AM -0400, Alan Stern wrote: > On Wed, 7 Apr 2010, Greg KH wrote: > > > Alan, any objection to just using usb_buffer_alloc() for every driver? > > Or is that too much overhead? > > I don't know what the overhead is. But usb_buffer_alloc() requires the > caller to keep track of the buffer's DMA address, so it's not a simple > plug-in replacement. In addition, the consistent memory that > usb_buffer_alloc() provides is a scarce resource on some platforms. > > Writing new functions is the way to go. Ok, I'll write some dummies for usb_malloc() and usb_zalloc() which will just call kmalloc() with GFP_DMA32 for now. And while at it, usb_alloc_buffer() will be renamed to usb_alloc_consistent(). Then I'll try to clean up all existing drivers to use this new interface and follow the changes. In a next step, we should fine-tune when GFP_DMA32 is really needed. And I'll leave all occurances of usb_alloc_consistent() as they are now. Does that sound ok? Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
