On Tue, 4 Oct 2016 18:55:54 +0200 Maxime Ripard maxime.ripard@free-electrons.com wrote:
On Tue, Oct 04, 2016 at 12:40:11PM +0200, Jean-Francois Moine wrote:
On Tue, 4 Oct 2016 11:46:14 +0200 Mylène Josserand mylene.josserand@free-electrons.com wrote:
Add the case of a burst of 4 which is handled by the SoC.
Signed-off-by: Mylène Josserand mylene.josserand@free-electrons.com
drivers/dma/sun6i-dma.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 8346199..0485204 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) switch (maxburst) { case 1: return 0;
- case 4:
return 1;-- 2.9.3
This patch has already been rejected by Maxime in the threads http://www.spinics.net/lists/dmaengine/msg08610.html and http://www.spinics.net/lists/dmaengine/msg08719.html
I hope you will find the way he wants for this maxburst to be added.
I was talking about something along these lines (not tested):
I wonder why you don't submit this yourself.
-------8<--------- diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 83461994e418..573ac4608293 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) switch (maxburst) { case 1: return 0;
- case 4:
return 1;@@ -1110,11 +1112,19 @@ static int sun6i_dma_probe(struct platform_device *pdev) sdc->slave.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
sdc->slave.dst_bursts = BIT(1) | BIT(8);
sdc->slave.src_bursts = BIT(1) | BIT(8); sdc->slave.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); sdc->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; sdc->slave.dev = &pdev->dev;
if (of_device_is_compatible(pdev->dev.of_node,
"allwinner,sun8i-h3-dma")) {sdc->slave.dst_bursts |= BIT(4);sdc->slave.src_bursts |= BIT(4);}
sdc->pchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_channels, sizeof(struct sun6i_pchan), GFP_KERNEL); if (!sdc->pchans)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cc535a478bae..f7bbec24bb58 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -673,6 +673,8 @@ struct dma_filter {
- each type of direction, the dma controller should fill (1 <<
- <TYPE>) and same should be checked by controller as well
- @max_burst: max burst capability per-transfer
- @dst_bursts: bitfield of the available burst sizes for the destination
- @src_bursts: bitfield of the available burst sizes for the source
You did not define dst_bursts nor src_bursts.
- @residue_granularity: granularity of the transfer residue reported
- by tx_status
- @device_alloc_chan_resources: allocate resources and return the
@@ -800,6 +802,14 @@ struct dma_device { static inline int dmaengine_slave_config(struct dma_chan *chan, struct dma_slave_config *config) {
- if (config->src_maxburst && config->device->src_bursts &&
!(BIT(config->src_maxburst) & config->device->src_bursts))
The maxburst may be as big as 4Kibytes, then, I am not sure that this code will work!
return -EINVAL;- if (config->dst_maxburst && config->device->dst_bursts &&
!(BIT(config->dst_maxburst) & config->device->dst_bursts))return -EINVAL;- if (chan->device->device_config) return chan->device->device_config(chan, config);
-------8<------------
Yes, I know that the burst size is always a power of 2. The best way to check it would be to change the {src,dts}_maxburst to a bitmap of the possible bursts as 0x0d for 1,4 and 8 bytes. But this asks for a lot of changes...