[PATCH v2 3/8] dmaengine: dw: replace convert_burst() with one liner

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxxxxxxxx>
---
 drivers/dma/dw/core.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 482ca979e573..7f2624f30416 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -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;
 }
-- 
2.11.0

--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux PCI]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux