@@ -901,25 +901,18 @@ bool dw_dma_filter(struct dma_chan *chan, void *param)
}
EXPORT_SYMBOL_GPL(dw_dma_filter);
-/*
- * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
- * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
- *
- * NOTE: burst size 2 is not supported by controller.
- *
- * This can be done by finding least significant bit set: n & (n - 1)
- */
-static inline void convert_burst(u32 *maxburst)
-{
- if (*maxburst > 1)
- *maxburst = fls(*maxburst) - 2;
- else
- *maxburst = 0;
-}
-
static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+ struct dma_slave_config *sc = &dwc->dma_sconfig;
+ /*
+ * Fix sconfig's burst size according to dw_dmac. We need to convert
+ * them as:
+ * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
+ *
+ * NOTE: burst size 2 is not supported by DesignWare controller.
+ */
+ u32 s = 2;
/* Check if chan will be configured for slave transfers */
if (!is_slave_direction(sconfig->direction))
@@ -928,8 +921,8 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
dwc->direction = sconfig->direction;
- convert_burst(&dwc->dma_sconfig.src_maxburst);
- convert_burst(&dwc->dma_sconfig.dst_maxburst);
+ sc->src_maxburst = sc->src_maxburst > 1 ? fls(sc->src_maxburst) - s : 0;
+ sc->dst_maxburst = sc->dst_maxburst > 1 ? fls(sc->dst_maxburst) - s : 0;
return 0;
}
Replace convert_burst() with one liner in place. The change simplifies further extension of the driver to cover new DMA controller hardware. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/dma/dw/core.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-)