| Message ID | 1957017.QzKNMJJqD6@bear (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Tue, Feb 6, 2018 at 1:24 PM, Frank Mori Hess <fmh6jj@gmail.com> wrote: > > 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), with a 4.1 kernel. > The port of my changes to HEAD has only been tested to compile. > I'm willing to try to test on my hardware with a HEAD kernel > and try using the dmatest module to test memory-to-memory > transfers if this patch might be accepted. > > Signed-off-by: Frank Mori Hess <fmh6jj@gmail.com> I've now tested my patch with hardware using the Linux 4.15 dmaengine code, and used the dmatest module to test mem-to-mem transfers. Tested-by: Frank Mori Hess <fmh6jj@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Feb 06, 2018 at 01:24:38PM -0500, Frank Mori Hess wrote: > Resending same patch as before, except not corrupted by word-wrap this > time. This is useless for changelog.. > > Do DMAFLUSHP _before_ the first DMAWFP to insure controller do you mean ensure..? > 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. > > 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), with a 4.1 kernel. > The port of my changes to HEAD has only been tested to compile. > I'm willing to try to test on my hardware with a HEAD kernel > and try using the dmatest module to test memory-to-memory > transfers if this patch might be accepted. This one as well, pls move this after s-o-b line, which give reviewer and maintainer context but don't get applied.. > > Signed-off-by: Frank Mori Hess <fmh6jj@gmail.com> > --- > drivers/dma/pl330.c | 131 ++++++++++++++++++++++++++++++++++------------------ > 1 file changed, 87 insertions(+), 44 deletions(-) This has too many style issues, please run ./scripts/checkpatch.pl on the patch. It should have 0 errors, pls use your discretion for warnings Right now it shows: total: 19 errors, 21 warnings *Also* CC Maintainers, ./scripts/get_maintainer.pl will tell you whom to CC. Maintainers might miss the patch if not CCed... > > diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c > index d7327fd5f445..5a3e80ec4b0b 100644 > --- a/drivers/dma/pl330.c > +++ b/drivers/dma/pl330.c > @@ -1094,26 +1094,27 @@ 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 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 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_LDP(dry_run, &buf[off], cond, pxs->desc->peri); > + if(cond == ALWAYS) { > + off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri); > + off += _emit_LDP(dry_run, &buf[off], BURST, pxs->desc->peri); > + }else { > + off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri); > + } > off += _emit_ST(dry_run, &buf[off], ALWAYS); > - > - if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)) > - off += _emit_FLUSHP(dry_run, &buf[off], > - pxs->desc->peri); > } > > return off; > @@ -1121,24 +1122,26 @@ static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run, > > 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 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); > + } > } > > return off; > @@ -1148,13 +1151,14 @@ static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], > const struct _xfer_spec *pxs, int cyc) > { > int off = 0; > - > + enum pl330_cond cond = BRST_LEN(pxs->ccr) > 1 ? BURST : SINGLE; > + > switch (pxs->desc->rqtype) { > case DMA_MEM_TO_DEV: > - off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc); > + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc, cond); > break; > case DMA_DEV_TO_MEM: > - off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc); > + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc, cond); > break; > case DMA_MEM_TO_MEM: > off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc); > @@ -1167,6 +1171,39 @@ static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], > return off; > } > > +/* transfer dregs with single transfers to peripheral, or a reduced size burst > + * for mem-to-mem. */ > +static int _dregs(struct pl330_dmac *pl330, unsigned 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; > + 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 */ > + break; > + } > + > + return off; > +} > + > /* Returns bytes consumed and updates bursts */ > static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], > unsigned long *bursts, const struct _xfer_spec *pxs) > @@ -1256,6 +1293,7 @@ static inline int _setup_loops(struct pl330_dmac *pl330, > struct pl330_xfer *x = &pxs->desc->px; > u32 ccr = pxs->ccr; > unsigned long c, bursts = BYTE_TO_BURST(x->bytes, ccr); > + int num_dregs = (x->bytes - BURST_TO_BYTE(bursts, ccr)) / BRST_SIZE(ccr); > int off = 0; > > while (bursts) { > @@ -1263,7 +1301,8 @@ static inline int _setup_loops(struct pl330_dmac *pl330, > off += _loop(pl330, dry_run, &buf[off], &c, pxs); > bursts -= c; > } > - > + off += _dregs(pl330, dry_run, &buf[off], pxs, num_dregs); > + > return off; > } > > @@ -1294,7 +1333,6 @@ static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run, > struct _xfer_spec *pxs) > { > struct _pl330_req *req = &thrd->req[index]; > - struct pl330_xfer *x; > u8 *buf = req->mc_cpu; > int off = 0; > > @@ -1303,11 +1341,6 @@ 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 +2148,31 @@ 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; > + 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; > } > > return 0; > @@ -2517,14 +2566,8 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) > burst_len >>= desc->rqcfg.brst_size; > > /* src/dst_burst_len can't be more than 16 */ > - if (burst_len > 16) > - burst_len = 16; > - > - while (burst_len > 1) { > - if (!(len % (burst_len << desc->rqcfg.brst_size))) > - break; > - burst_len--; > - } > + if (burst_len > PL330_MAX_BURST) > + burst_len = PL330_MAX_BURST; > > return burst_len; > } > @@ -2596,7 +2639,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic( > > desc->rqtype = direction; > desc->rqcfg.brst_size = pch->burst_sz; > - desc->rqcfg.brst_len = 1; > + desc->rqcfg.brst_len = pch->burst_len; > desc->bytes_requested = period_len; > fill_px(&desc->px, dst, src, period_len); > > @@ -2741,7 +2784,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, > } > > desc->rqcfg.brst_size = pch->burst_sz; > - desc->rqcfg.brst_len = 1; > + desc->rqcfg.brst_len = pch->burst_len; > desc->rqtype = direction; > desc->bytes_requested = sg_dma_len(sg); > } > -- > 2.11.0 > > > > -- > To unsubscribe from this list: send the line "unsubscribe dmaengine" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index d7327fd5f445..5a3e80ec4b0b 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -1094,26 +1094,27 @@ 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 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 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_LDP(dry_run, &buf[off], cond, pxs->desc->peri); + if(cond == ALWAYS) { + off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri); + off += _emit_LDP(dry_run, &buf[off], BURST, pxs->desc->peri); + }else { + off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri); + } off += _emit_ST(dry_run, &buf[off], ALWAYS); - - if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)) - off += _emit_FLUSHP(dry_run, &buf[off], - pxs->desc->peri); } return off; @@ -1121,24 +1122,26 @@ static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run, 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 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); + } } return off; @@ -1148,13 +1151,14 @@ static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], const struct _xfer_spec *pxs, int cyc) { int off = 0; - + enum pl330_cond cond = BRST_LEN(pxs->ccr) > 1 ? BURST : SINGLE; + switch (pxs->desc->rqtype) { case DMA_MEM_TO_DEV: - off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc); + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc, cond); break; case DMA_DEV_TO_MEM: - off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc); + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc, cond); break; case DMA_MEM_TO_MEM: off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc); @@ -1167,6 +1171,39 @@ static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], return off; } +/* transfer dregs with single transfers to peripheral, or a reduced size burst + * for mem-to-mem. */ +static int _dregs(struct pl330_dmac *pl330, unsigned 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; + 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 */ + break; + } + + return off; +} + /* Returns bytes consumed and updates bursts */ static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], unsigned long *bursts, const struct _xfer_spec *pxs) @@ -1256,6 +1293,7 @@ static inline int _setup_loops(struct pl330_dmac *pl330, struct pl330_xfer *x = &pxs->desc->px; u32 ccr = pxs->ccr; unsigned long c, bursts = BYTE_TO_BURST(x->bytes, ccr); + int num_dregs = (x->bytes - BURST_TO_BYTE(bursts, ccr)) / BRST_SIZE(ccr); int off = 0; while (bursts) { @@ -1263,7 +1301,8 @@ static inline int _setup_loops(struct pl330_dmac *pl330, off += _loop(pl330, dry_run, &buf[off], &c, pxs); bursts -= c; } - + off += _dregs(pl330, dry_run, &buf[off], pxs, num_dregs); + return off; } @@ -1294,7 +1333,6 @@ static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run, struct _xfer_spec *pxs) { struct _pl330_req *req = &thrd->req[index]; - struct pl330_xfer *x; u8 *buf = req->mc_cpu; int off = 0; @@ -1303,11 +1341,6 @@ 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 +2148,31 @@ 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; + 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; } return 0; @@ -2517,14 +2566,8 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) burst_len >>= desc->rqcfg.brst_size; /* src/dst_burst_len can't be more than 16 */ - if (burst_len > 16) - burst_len = 16; - - while (burst_len > 1) { - if (!(len % (burst_len << desc->rqcfg.brst_size))) - break; - burst_len--; - } + if (burst_len > PL330_MAX_BURST) + burst_len = PL330_MAX_BURST; return burst_len; } @@ -2596,7 +2639,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic( desc->rqtype = direction; desc->rqcfg.brst_size = pch->burst_sz; - desc->rqcfg.brst_len = 1; + desc->rqcfg.brst_len = pch->burst_len; desc->bytes_requested = period_len; fill_px(&desc->px, dst, src, period_len); @@ -2741,7 +2784,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, } desc->rqcfg.brst_size = pch->burst_sz; - desc->rqcfg.brst_len = 1; + desc->rqcfg.brst_len = pch->burst_len; desc->rqtype = direction; desc->bytes_requested = sg_dma_len(sg); }
Resending same patch as before, except not corrupted by word-wrap this time. Do DMAFLUSHP _before_ the first DMAWFP to insure 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. 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), with a 4.1 kernel. The port of my changes to HEAD has only been tested to compile. I'm willing to try to test on my hardware with a HEAD kernel and try using the dmatest module to test memory-to-memory transfers if this patch might be accepted. Signed-off-by: Frank Mori Hess <fmh6jj@gmail.com> --- drivers/dma/pl330.c | 131 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 87 insertions(+), 44 deletions(-)