From: sugar zhang <sugar.zhang@rock-chips.com>
To: Vinod Koul <vkoul@kernel.org>
Cc: Heiko Stuebner <heiko@sntech.de>,
linux-rockchip@lists.infradead.org,
Dan Williams <dan.j.williams@intel.com>,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 01/13] dmaengine: pl330: Remove the burst limit for quirk 'NO-FLUSHP'
Date: Mon, 29 Jun 2020 09:38:54 +0800 [thread overview]
Message-ID: <879c88ef-1d74-26d5-1641-efeb450362fa@rock-chips.com> (raw)
In-Reply-To: <20200624075437.GT2324254@vkoul-mobl>
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
>>
>>
--
next prev parent reply other threads:[~2020-06-29 1:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-09 1:14 [PATCH v2 0/13] Patches to improve transfer efficiency for Rockchip SoCs Sugar Zhang
2020-06-09 1:14 ` [PATCH v2 01/13] dmaengine: pl330: Remove the burst limit for quirk 'NO-FLUSHP' Sugar Zhang
2020-06-24 7:54 ` Vinod Koul
2020-06-29 1:38 ` sugar zhang [this message]
2020-06-09 1:14 ` [PATCH v2 02/13] dmaengine: pl330: Add quirk 'arm,pl330-periph-burst' Sugar Zhang
2020-06-24 8:19 ` Vinod Koul
2020-06-09 1:14 ` [PATCH v2 03/13] dt-bindings: dma: pl330: Document the " Sugar Zhang
2020-06-17 20:58 ` Rob Herring
2020-06-12 1:06 ` [PATCH v2 0/13] Patches to improve transfer efficiency for Rockchip SoCs Peter Geis
2020-06-12 1:15 ` Peter Geis
2020-06-12 8:58 ` sugar zhang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=879c88ef-1d74-26d5-1641-efeb450362fa@rock-chips.com \
--to=sugar.zhang@rock-chips.com \
--cc=dan.j.williams@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=heiko@sntech.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).