dmaengine Archive on lore.kernel.org
 help / color / Atom feed
From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Vinod Koul <vkoul@kernel.org>, Viresh Kumar <vireshk@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Dan Williams <dan.j.williams@intel.com>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
	Serge Semin <fancer.lancer@gmail.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Rob Herring <robh+dt@kernel.org>, <dmaengine@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v8 07/10] dmaengine: dw: Set DMA device max segment size parameter
Date: Thu, 23 Jul 2020 03:58:45 +0300
Message-ID: <20200723005848.31907-8-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200723005848.31907-1-Sergey.Semin@baikalelectronics.ru>

Maximum block size DW DMAC configuration corresponds to the max segment
size DMA parameter in the DMA core subsystem notation. Lets set it with a
value specific to the probed DW DMA controller. It shall help the DMA
clients to create size-optimized SG-list items for the controller. This in
turn will cause less dw_desc allocations, less LLP reinitializations,
better DMA device performance.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

---

Changelog v2:
- This is a new patch created in place of the dropped one:
  "dmaengine: dw: Add LLP and block size config accessors".

Changelog v3:
- Use the block_size found for the very first channel instead of looking for
  the maximum of maximum block sizes.
- Don't define device-specific device_dma_parameters object, since it has
  already been defined by the platform device core.
---
 drivers/dma/dw/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 33e99d95b3d3..fb95920c429e 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1229,6 +1229,13 @@ int do_dma_probe(struct dw_dma_chip *chip)
 			     BIT(DMA_MEM_TO_MEM);
 	dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 
+	/*
+	 * For now there is no hardware with non uniform maximum block size
+	 * across all of the device channels, so we set the maximum segment
+	 * size as the block size found for the very first channel.
+	 */
+	dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size);
+
 	err = dma_async_device_register(&dw->dma);
 	if (err)
 		goto err_dma_register;
-- 
2.26.2


  parent reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  0:58 [PATCH v8 00/10] dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account Serge Semin
2020-07-23  0:58 ` [PATCH v8 01/10] dt-bindings: dma: dw: Convert DW DMAC to DT binding Serge Semin
2020-07-23  0:58 ` [PATCH v8 02/10] dt-bindings: dma: dw: Add max burst transaction length property Serge Semin
2020-07-23  0:58 ` [PATCH v8 03/10] dmaengine: Introduce min burst length capability Serge Semin
2020-07-23  0:58 ` [PATCH v8 04/10] dmaengine: Introduce max SG burst capability Serge Semin
2020-07-23  0:58 ` [PATCH v8 05/10] dmaengine: Introduce DMA-device device_caps callback Serge Semin
2020-07-23  0:58 ` [PATCH v8 06/10] dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config Serge Semin
2020-07-23  0:58 ` Serge Semin [this message]
2020-07-23  0:58 ` [PATCH v8 08/10] dmaengine: dw: Initialize min and max burst DMA device capability Serge Semin
2020-07-23  0:58 ` [PATCH v8 09/10] dmaengine: dw: Introduce max burst length hw config Serge Semin
2020-07-23  0:58 ` [PATCH v8 10/10] dmaengine: dw: Initialize max_sg_burst capability Serge Semin
2020-07-27  9:01 ` [PATCH v8 00/10] dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account Vinod Koul
2020-07-27 20:55   ` Serge Semin

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=20200723005848.31907-8-Sergey.Semin@baikalelectronics.ru \
    --to=sergey.semin@baikalelectronics.ru \
    --cc=Alexey.Malahov@baikalelectronics.ru \
    --cc=Pavel.Parkhomenko@baikalelectronics.ru \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=andy.shevchenko@gmail.com \
    --cc=dan.j.williams@intel.com \
    --cc=devicetree@vger.kernel.org \
    --cc=dmaengine@vger.kernel.org \
    --cc=fancer.lancer@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peter.ujfalusi@ti.com \
    --cc=robh+dt@kernel.org \
    --cc=vireshk@kernel.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

dmaengine Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/dmaengine/0 dmaengine/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dmaengine dmaengine/ https://lore.kernel.org/dmaengine \
		dmaengine@vger.kernel.org
	public-inbox-index dmaengine

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.dmaengine


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git