On Sat, Nov 11, 2017 at 07:21:24PM +0900, David Miller wrote: > From: Mika Westerberg <mika.westerb...@linux.intel.com> > Date: Thu, 9 Nov 2017 13:46:28 +0300 > > > When Thunderbolt network interface is disabled or when the cable is > > unplugged the driver releases all allocated buffers by calling > > tbnet_free_buffers() for each ring. This function then calls > > dma_unmap_page() for each buffer it finds where bus address is non-zero. > > Now, we only clear this bus address when the Tx buffer is sent to the > > hardware so it is possible that the function finds an entry that has > > already been unmapped. > > > > Enabling DMA-API debugging catches this as well: > > > > thunderbolt 0000:06:00.0: DMA-API: device driver tries to free DMA > > memory it has not allocated [device address=0x0000000068321000] > > [size=4096 bytes] > > > > Fix this by clearing the bus address of a Tx frame right after we have > > unmapped the buffer. > > > > Signed-off-by: Mika Westerberg <mika.westerb...@linux.intel.com> > > Applied, but assuming zero is a non-valid DMA address is never a good > idea. That's why we have the DMA error code signaling abstracted.
There does not seem to be a way to mark DMA address invalid in a driver so we probably need to add a flag to struct tbnet_frame instead.
