On Tue, Oct 25, 2016 at 10:22:29AM +0200, Thierry Escande wrote: > From: Pawel Osciak <posciak@xxxxxxxxxxxx> > > When this flag is set for CAPTURE queues by the driver on calling > vb2_queue_init(), it forces the buffers on the queue to be > allocated/mapped with DMA_BIDIRECTIONAL direction flag instead of > DMA_FROM_DEVICE. This allows the device not only to write to the > buffers, but also read out from them. This may be useful e.g. for codec > hardware which may be using CAPTURE buffers as reference to decode > other buffers. > > This flag is ignored for OUTPUT queues as we don't want to allow HW to > be able to write to OUTPUT buffers. > > This patch introduces 2 macros: > VB2_DMA_DIR(q) returns the corresponding dma_dir for the passed queue > type, tanking care of the capture_dma_birectional flag. > > VB2_DMA_DIR_CAPTURE(d) is a test macro returning true if the passed DMA > direction refers to a capture buffer. This test is used to map virtual > addresses for writing and to mark pages as dirty. > > Signed-off-by: Pawel Osciak <posciak@xxxxxxxxxxxx> > Tested-by: Pawel Osciak <posciak@xxxxxxxxxxxx> > Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> -- Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- 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
