On Sun, 6 Mar 2011 16:06:38 +0100 Oliver Neukum <oliver@xxxxxxxxxx> wrote: > Am Sonntag, 6. März 2011, 15:38:05 schrieb Florian Mickler: > > On Sun, 6 Mar 2011 13:06:09 +0100 > > Oliver Neukum <oliver@xxxxxxxxxx> wrote: > > > > > Am Sonntag, 6. März 2011, 12:16:52 schrieb Florian Mickler: > > > > > Please take a look at it, as I do not do that much kernel hacking > > > > and don't wanna brake anybodys computer... :) > > > > > > > > From my point of view this should _not_ go to stable even though it would > > > > be applicable. But if someone feels strongly about that and can > > > > take responsibility for that change... > > > > > > The patch looks good and is needed in stable. > > > It could be improved by using a buffer allocated once in the places > > > you hold a mutex anyway. > > > > > > Regards > > > Oliver > > > > Ok, I now put a buffer member in the priv dib0700_state which gets > > allocated on the heap. > > This however is wrong. Just like DMA on the stack this breaks > coherency rules. You may do DMA to the heap in the sense that > you can do DMA to buffers allocated on the heap, but you cannot > do DMA to a part of another structure allocated on the heap. > You need a separate kmalloc for each buffer. > You can reuse the buffer with proper locking, but you must allocate > it seperately once. > > Regards > Oliver Hm.. allocating the buffer in the probe routine and deallocating it in the usb_driver disconnect callback should work? How come that it must be a seperate kmalloc buffer? Is it some aligning that kmalloc garantees? Regards, Flo -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
