Messages in this thread | | | Subject | Re: [PATCH v2 01/13] dmaengine: pl330: Remove the burst limit for quirk 'NO-FLUSHP' | From | sugar zhang <> | Date | Mon, 29 Jun 2020 09:38:54 +0800 |
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On 2020/6/24 15:54, Vinod Koul wrote: > On 09-06-20, 09:14, Sugar Zhang wrote: >> There is no reason to limit the performance on the 'NO-FLUSHP' SoCs, >> cuz these platforms are just that the 'FLUSHP' instruction is broken. > Lets not use terms like cuz... 'because' is perfect term :) > > It can rephrased to: > There is no reason to limit the performance on the 'NO-FLUSHP' SoCs > beacuse 'FLUSHP' instruction is broken on these platforms, so remove the > limit to improve the efficiency Thanks, I will send a v3 including these. > >> so, remove the limit to improve the efficiency. >> >> Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com> >> --- >> >> Changes in v2: None >> >> drivers/dma/pl330.c | 34 ++++++++++++++++++++++------------ >> 1 file changed, 22 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c >> index 6a158ee..ff0a91f 100644 >> --- a/drivers/dma/pl330.c >> +++ b/drivers/dma/pl330.c >> @@ -1183,9 +1183,6 @@ static inline int _ldst_peripheral(struct pl330_dmac *pl330, >> { >> int off = 0; >> >> - if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) >> - cond = BURST; >> - >> /* >> * do FLUSHP at beginning to clear any stale dma requests before the >> * first WFP. >> @@ -1231,8 +1228,9 @@ static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[], >> } >> >> /* >> - * transfer dregs with single transfers to peripheral, or a reduced size burst >> - * for mem-to-mem. >> + * only the unaligned bursts transfers have the dregs. >> + * transfer dregs with a reduced size burst to peripheral, >> + * or a reduced size burst for mem-to-mem. > This is not related to broken flush and should be a different patch > explaining why this changes were done ok, I will split this patch in v3. >> */ >> static int _dregs(struct pl330_dmac *pl330, unsigned int dry_run, u8 buf[], >> const struct _xfer_spec *pxs, int transfer_length) >> @@ -1247,8 +1245,23 @@ static int _dregs(struct pl330_dmac *pl330, unsigned int dry_run, u8 buf[], >> case DMA_MEM_TO_DEV: >> /* fall through */ >> case DMA_DEV_TO_MEM: >> - off += _ldst_peripheral(pl330, dry_run, &buf[off], pxs, >> - transfer_length, SINGLE); >> + /* >> + * dregs_len = (total bytes - BURST_TO_BYTE(bursts, ccr)) / >> + * BRST_SIZE(ccr) >> + * the dregs len must be smaller than burst len, >> + * so, for higher efficiency, we can modify CCR >> + * to use a reduced size burst len for the dregs. >> + */ >> + 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_peripheral(pl330, dry_run, &buf[off], pxs, 1, >> + BURST); >> break; >> >> case DMA_MEM_TO_MEM: >> @@ -2221,9 +2234,7 @@ static bool pl330_prep_slave_fifo(struct dma_pl330_chan *pch, >> >> static int fixup_burst_len(int max_burst_len, int quirks) >> { >> - if (quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) >> - return 1; >> - else if (max_burst_len > PL330_MAX_BURST) >> + if (max_burst_len > PL330_MAX_BURST) >> return PL330_MAX_BURST; >> else if (max_burst_len < 1) >> return 1; >> @@ -3128,8 +3139,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) >> pd->dst_addr_widths = PL330_DMA_BUSWIDTHS; >> pd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); >> pd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; >> - pd->max_burst = ((pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP) ? >> - 1 : PL330_MAX_BURST); >> + pd->max_burst = PL330_MAX_BURST; >> >> ret = dma_async_device_register(pd); >> if (ret) { >> -- >> 2.7.4 >> >> --
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