diff options
| -rw-r--r-- | drivers/dma/omap-dma.c | 52 |
1 files changed, 29 insertions, 23 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index a1baada7dcd4..1e0018f36384 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -451,28 +451,39 @@ static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr) return size; } +/* + * OMAP 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is + * read before the DMA controller finished disabling the channel. + */ +static uint32_t omap_dma_chan_read_3_3(struct omap_chan *c, unsigned reg) +{ + struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device); + uint32_t val; + + val = omap_dma_chan_read(c, reg); + if (val == 0 && od->plat->errata & DMA_ERRATA_3_3) + val = omap_dma_chan_read(c, reg); + + return val; +} + static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c) { struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device); - dma_addr_t addr; + dma_addr_t addr, cdac; - if (__dma_omap15xx(od->plat->dma_attr)) + if (__dma_omap15xx(od->plat->dma_attr)) { addr = omap_dma_chan_read(c, CPC); - else - addr = omap_dma_chan_read(c, CSAC); - - if (od->plat->errata & DMA_ERRATA_3_3 && addr == 0) - addr = omap_dma_chan_read(c, CSAC); + } else { + addr = omap_dma_chan_read_3_3(c, CSAC); + cdac = omap_dma_chan_read_3_3(c, CDAC); - if (!__dma_omap15xx(od->plat->dma_attr)) { /* * CDAC == 0 indicates that the DMA transfer on the channel has * not been started (no data has been transferred so far). * Return the programmed source start address in this case. */ - if (omap_dma_chan_read(c, CDAC)) - addr = omap_dma_chan_read(c, CSAC); - else + if (cdac == 0) addr = omap_dma_chan_read(c, CSSA); } @@ -487,21 +498,16 @@ static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c) struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device); dma_addr_t addr; - if (__dma_omap15xx(od->plat->dma_attr)) + if (__dma_omap15xx(od->plat->dma_attr)) { addr = omap_dma_chan_read(c, CPC); - else - addr = omap_dma_chan_read(c, CDAC); + } else { + addr = omap_dma_chan_read_3_3(c, CDAC); - /* - * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is - * read before the DMA controller finished disabling the channel. - */ - if (!__dma_omap15xx(od->plat->dma_attr) && addr == 0) { - addr = omap_dma_chan_read(c, CDAC); /* - * CDAC == 0 indicates that the DMA transfer on the channel has - * not been started (no data has been transferred so far). - * Return the programmed destination start address in this case. + * CDAC == 0 indicates that the DMA transfer on the channel + * has not been started (no data has been transferred so + * far). Return the programmed destination start address in + * this case. */ if (addr == 0) addr = omap_dma_chan_read(c, CDSA); |