On Wednesday 09 May 2007, Laurent Pinchart wrote: > Could you elaborate a bit on the subject ? Which allocator calls should I > use ? Just kmalloc ? When does a USB driver need cache coherent buffers ?
Using kmalloc() should be fine. The original use-case for cache-coherent DMA buffers was HID on SPARC, for keyboard and mouse. The HID report buffers are about 8 bytes, and using dma-coherent buffers was a *lot* cheaper than IOMMU operation for dma map/unmap on every keystroke or mouse gesture. - Dave ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
