On Tue, 4 Oct 2016 18:55:54 +0200 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx> wrote: > > > > > Add the case of a burst of 4 which is handled by the SoC. > > > > > > Signed-off-by: Mylène Josserand <mylene.josserand@xxxxxxxxxxxxxxxxxx> > > > --- > > > 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; > > > case 8: > > > return 2; > > > default: > > > -- > > > 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; > case 8: > return 2; > default: > @@ -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... -- Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html