On Tue, Mar 06, 2018 at 11:03:22AM -0500, Frank Mori Hess wrote: > Do DMAFLUSHP _before_ the first DMAWFP to ensure controller > and peripheral are in agreement about dma request state before first > transfer. Add support for burst transfers to/from peripherals. In the new > scheme, the controller does as many burst transfers as it can then > transfers the remaining dregs with either single transfers for > peripherals, or with a reduced size burst for memory-to-memory transfers. > > Signed-off-by: Frank Mori Hess <fmh6jj@xxxxxxxxx> > Tested-by: Frank Mori Hess <fmh6jj@xxxxxxxxx> sorry if it wasnt clear earlier, the lines below should come after the --- line. git-am skips that part while applying.. > > I tested dma transfers to peripherals with designware serial port > (drivers/tty/serial/8250/8250_dw.c) and a GPIB interface > (https://github.com/fmhess/fmh_gpib_core). I tested memory-to-memory > transfers using the dmatest module. > > v3 of this patch should be the same as v2 except with checkpatch.pl > warnings and errors cleaned up. > > --- > drivers/dma/pl330.c | 146 +++++++++++++++++++++++++++++++++++++--------------- > 1 file changed, 104 insertions(+), 42 deletions(-) > > diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c > index d7327fd5f445..cc2e4456bec1 100644 > --- a/drivers/dma/pl330.c > +++ b/drivers/dma/pl330.c > @@ -1094,26 +1094,33 @@ static inline int _ldst_memtomem(unsigned dry_run, u8 buf[], > return off; > } > > -static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run, > - u8 buf[], const struct _xfer_spec *pxs, > - int cyc) > +static inline int _ldst_devtomem(struct pl330_dmac *pl330, > + unsigned int dry_run, u8 buf[], > + const struct _xfer_spec *pxs, > + int cyc, enum pl330_cond cond) > { > int off = 0; > - enum pl330_cond cond; > > if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) > cond = BURST; > - else > - cond = SINGLE; > > + /* do FLUSHP at beginning to clear any stale dma requests before the > + * first WFP. > + */ multiline comments should be: /* * this is an example of multi-line * comment */ Pls fix at this and other places... > static inline int _ldst_memtodev(struct pl330_dmac *pl330, > unsigned dry_run, u8 buf[], > - const struct _xfer_spec *pxs, int cyc) > + const struct _xfer_spec *pxs, int cyc, > + enum pl330_cond cond) > { > int off = 0; > - enum pl330_cond cond; > > if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) > cond = BURST; > - else > - cond = SINGLE; > > + /* do FLUSHP at beginning to clear any stale dma requests before the > + * first WFP. > + */ > + if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)) > + off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri); > while (cyc--) { > off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri); > off += _emit_LD(dry_run, &buf[off], ALWAYS); > - off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri); > - > - if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)) > - off += _emit_FLUSHP(dry_run, &buf[off], > - pxs->desc->peri); > + if (cond == ALWAYS) { > + off += _emit_STP(dry_run, &buf[off], SINGLE, > + pxs->desc->peri); > + off += _emit_STP(dry_run, &buf[off], BURST, > + pxs->desc->peri); > + } else { > + off += _emit_STP(dry_run, &buf[off], cond, > + pxs->desc->peri); > + } this looks quite similar to previous routine above, if so can we please make it common function and invoke from both of these... > +static int _dregs(struct pl330_dmac *pl330, unsigned int dry_run, u8 buf[], > + const struct _xfer_spec *pxs, int transfer_length) > +{ > + int off = 0; > + int dregs_ccr; > + > + if (transfer_length == 0) > + return off; > + > + switch (pxs->desc->rqtype) { > + case DMA_MEM_TO_DEV: > + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, > + transfer_length, SINGLE); > + break; empty line after each case pls > + case DMA_DEV_TO_MEM: > + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, > + transfer_length, SINGLE); > + break; > + case DMA_MEM_TO_MEM: > + dregs_ccr = pxs->ccr; > + dregs_ccr &= ~((0xf << CC_SRCBRSTLEN_SHFT) | > + (0xf << CC_DSTBRSTLEN_SHFT)); > + dregs_ccr |= (((transfer_length - 1) & 0xf) << > + CC_SRCBRSTLEN_SHFT); > + dregs_ccr |= (((transfer_length - 1) & 0xf) << > + CC_DSTBRSTLEN_SHFT); > + off += _emit_MOV(dry_run, &buf[off], CCR, dregs_ccr); > + off += _ldst_memtomem(dry_run, &buf[off], pxs, 1); > + break; > + default: > + off += 0x40000000; /* Scare off the Client */ Can you explain this bit, shouldnt this be err? > @@ -1303,11 +1362,6 @@ static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run, > /* DMAMOV CCR, ccr */ > off += _emit_MOV(dry_run, &buf[off], CCR, pxs->ccr); > > - x = &pxs->desc->px; > - /* Error if xfer length is not aligned at burst size */ > - if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr))) > - return -EINVAL; > - > off += _setup_xfer(pl330, dry_run, &buf[off], pxs); > > /* DMASEV peripheral/event */ > @@ -2115,15 +2169,29 @@ static int pl330_config(struct dma_chan *chan, > pch->fifo_addr = slave_config->dst_addr; > if (slave_config->dst_addr_width) > pch->burst_sz = __ffs(slave_config->dst_addr_width); > - if (slave_config->dst_maxburst) > - pch->burst_len = slave_config->dst_maxburst; > + if (pch->dmac->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) > + pch->burst_len = 1; so in this case we don't honour the requested burst length? > + else if (slave_config->dst_maxburst) { > + if (slave_config->dst_maxburst > PL330_MAX_BURST) > + pch->burst_len = PL330_MAX_BURST; > + else > + pch->burst_len = slave_config->dst_maxburst; > + } else > + pch->burst_len = 1; > } else if (slave_config->direction == DMA_DEV_TO_MEM) { > if (slave_config->src_addr) > pch->fifo_addr = slave_config->src_addr; > if (slave_config->src_addr_width) > pch->burst_sz = __ffs(slave_config->src_addr_width); > - if (slave_config->src_maxburst) > - pch->burst_len = slave_config->src_maxburst; > + if (pch->dmac->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) > + pch->burst_len = 1; > + else if (slave_config->src_maxburst) { > + if (slave_config->src_maxburst > PL330_MAX_BURST) > + pch->burst_len = PL330_MAX_BURST; > + else > + pch->burst_len = slave_config->src_maxburst; > + } else > + pch->burst_len = 1; again this looks duplicate.. -- ~Vinod -- 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
