svn commit: r299679 - head/sys/dev/mmc/host

[Andrew Turner]

Author: andrew
Date: Fri May 13 15:15:54 2016
New Revision: 299679
URL: https://svnweb.freebsd.org/changeset/base/299679

Log:
  Add DMA sync operations around accessing the dwmmc descriptor ring. Even
  with it maps as cache-coherent we still need to call bus_dmamap_sync.
  
  Obtained from:	ABT Systems Ltd
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/sys/dev/mmc/host/dwmmc.c

Modified: head/sys/dev/mmc/host/dwmmc.c
==============================================================================
--- head/sys/dev/mmc/host/dwmmc.c	Fri May 13 15:11:17 2016	(r299678)
+++ head/sys/dev/mmc/host/dwmmc.c	Fri May 13 15:15:54 2016	(r299679)
@@ -722,6 +722,9 @@ dma_done(struct dwmmc_softc *sc, struct 
 		bus_dmamap_sync(sc->buf_tag, sc->buf_map,
 			BUS_DMASYNC_POSTREAD);
 
+	bus_dmamap_sync(sc->desc_tag, sc->desc_map,
+	    BUS_DMASYNC_POSTWRITE);
+
 	bus_dmamap_unload(sc->buf_tag, sc->buf_map);
 
 	return (0);
@@ -766,6 +769,10 @@ dma_prepare(struct dwmmc_softc *sc, stru
 	if (err != 0)
 		panic("dmamap_load failed\n");
 
+	/* Ensure the device can see the desc */
+	bus_dmamap_sync(sc->desc_tag, sc->desc_map,
+	    BUS_DMASYNC_PREWRITE);
+
 	if (data->flags & MMC_DATA_WRITE)
 		bus_dmamap_sync(sc->buf_tag, sc->buf_map,
 			BUS_DMASYNC_PREWRITE);