From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 368A8C433E0 for ; Wed, 24 Jun 2020 07:54:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F7F72088E for ; Wed, 24 Jun 2020 07:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592985283; bh=u5bGPxHpfck/MVpaAVun2T5RtLrj3PWfCkxiaVjC2tE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=d64K+bzVCz9Dvd5MJ5aZwEH/WYFOvNR3NRMxrDB2tMS7PzvoINOgeSUIiNfmXyHPq JZuV/S65COP57/lCr3aun7aipjw6jKzaYbGltW5UlpxGKjDKxWL/SKKwMfKA6AczDg uS7kBHtyW/vO+1/wr1gfKD0tNQfYDw18p+qKu+Ig= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389961AbgFXHym (ORCPT ); Wed, 24 Jun 2020 03:54:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:53082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388655AbgFXHym (ORCPT ); Wed, 24 Jun 2020 03:54:42 -0400 Received: from localhost (unknown [171.61.66.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A6D0E2085B; Wed, 24 Jun 2020 07:54:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592985281; bh=u5bGPxHpfck/MVpaAVun2T5RtLrj3PWfCkxiaVjC2tE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jUbxlwf7G39+dXkwsQB9wAmXBVX/OxV4FMeuXH3pSxehhaFfL6ituJFd22m2SfM7M kRNaK0kf1iLgAqLaX7GPsuQyJ0p3YY/4TWG69FbrQcfSOIPU9VXYI0pgt5cz86VfB0 14aLRMW8mG2ApfRAs08FVZyiLKjDvj769xv+UN2M= Date: Wed, 24 Jun 2020 13:24:37 +0530 From: Vinod Koul To: Sugar Zhang Cc: Heiko Stuebner , linux-rockchip@lists.infradead.org, Dan Williams , 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' Message-ID: <20200624075437.GT2324254@vkoul-mobl> References: <1591665267-37713-1-git-send-email-sugar.zhang@rock-chips.com> <1591665267-37713-2-git-send-email-sugar.zhang@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1591665267-37713-2-git-send-email-sugar.zhang@rock-chips.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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 > so, remove the limit to improve the efficiency. > > Signed-off-by: Sugar Zhang > --- > > 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 > */ > 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 > > -- ~Vinod