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>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh+dt@kernel.org>,
<linux-mips@vger.kernel.org>, <devicetree@vger.kernel.org>,
<dmaengine@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v3 07/10] dmaengine: dw: Set DMA device max segment size parameter
Date: Wed, 27 May 2020 01:50:18 +0300 [thread overview]
Message-ID: <20200526225022.20405-8-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200526225022.20405-1-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>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
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
next prev parent reply other threads:[~2020-05-26 22:51 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 22:50 [PATCH v3 00/10] dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account Serge Semin
2020-05-26 22:50 ` [PATCH v3 01/10] dt-bindings: dma: dw: Convert DW DMAC to DT binding Serge Semin
2020-05-26 22:50 ` [PATCH v3 02/10] dt-bindings: dma: dw: Add max burst transaction length property Serge Semin
2020-05-26 22:50 ` [PATCH v3 03/10] dmaengine: Introduce min burst length capability Serge Semin
2020-05-28 14:21 ` Andy Shevchenko
2020-05-26 22:50 ` [PATCH v3 04/10] dmaengine: Introduce max SG list entries capability Serge Semin
2020-05-28 14:22 ` Andy Shevchenko
2020-05-26 22:50 ` [PATCH v3 05/10] dmaengine: Introduce DMA-device device_caps callback Serge Semin
2020-05-28 14:42 ` Andy Shevchenko
2020-05-28 15:19 ` Serge Semin
2020-05-28 20:34 ` Andy Shevchenko
2020-05-26 22:50 ` [PATCH v3 06/10] dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config Serge Semin
2020-05-26 22:50 ` Serge Semin [this message]
2020-05-26 22:50 ` [PATCH v3 08/10] dmaengine: dw: Add dummy device_caps callback Serge Semin
2020-05-28 14:53 ` Andy Shevchenko
2020-05-28 15:27 ` Serge Semin
2020-05-28 20:29 ` Andy Shevchenko
2020-05-28 20:34 ` Serge Semin
2020-05-26 22:50 ` [PATCH v3 09/10] dmaengine: dw: Introduce max burst length hw config Serge Semin
2020-05-28 14:52 ` Andy Shevchenko
2020-05-28 15:40 ` Serge Semin
2020-05-28 19:53 ` Serge Semin
2020-05-28 20:38 ` Andy Shevchenko
2020-05-26 22:50 ` [PATCH v3 10/10] dmaengine: dw: Initialize max_sg_nents with nollp flag Serge Semin
2020-05-28 14:56 ` Andy Shevchenko
2020-05-28 15:50 ` Serge Semin
2020-05-28 20:31 ` Andy Shevchenko
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