Date:   Mon, 20 Mar 2023 15:14:01 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Cai Huoqing <cai.huoqing@linux.dev>
Cc:     Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: [PATCH v7 0/5] dmaengine: dw-edma: Add support for native HDMA
Message-ID: <20230320121401.zkcjbqmghzacpffh@mobilestation>
References: <20230315012840.6986-1-cai.huoqing@linux.dev>
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In-Reply-To: <20230315012840.6986-1-cai.huoqing@linux.dev>
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Hi Cai

On Wed, Mar 15, 2023 at 09:28:31AM +0800, Cai Huoqing wrote:
> Add support for HDMA NATIVE, as long the IP design has set
> the compatible register map parameter-HDMA_NATIVE,
> which allows compatibility for native HDMA register configuration.
> 
> The HDMA Hyper-DMA IP is an enhancement of the eDMA embedded-DMA IP.
> And the native HDMA registers are different from eDMA,
> so this patch add support for HDMA NATIVE mode.
> 
> HDMA write and read channels operate independently to maximize
> the performance of the HDMA read and write data transfer over
> the link When you configure the HDMA with multiple read channels,
> then it uses a round robin (RR) arbitration scheme to select
> the next read channel to be serviced.The same applies when
> youhave multiple write channels.
> 
> The native HDMA driver also supports a maximum of 16 independent
> channels (8 write + 8 read), which can run simultaneously.
> Both SAR (Source Address Register) and DAR (Destination Address Register)
> are aligned to byte.

It seems like we are getting towards the series finalization. I'll
test it out on my HW after v8 is submitted. Meanwhile could you please
clarify whether you have a real device with DW HDMA engine on board?
You keep submitting the DW eDMA driver core update, but there is no
glue-driver or low-level device driver patch for a real device which
would set the EDMA_MF_HDMA_NATIVE mapping.

-Serge(y)

> 
> Cai Huoqing (2):
>   dmaengine: dw-edma: Add support for native HDMA
>   dmaengine: dw-edma: Optimization in dw_edma_v0_core_handle_int
> 
> Cai huoqing (3):
>   dmaengine: dw-edma: Rename dw_edma_core_ops structure to
>     dw_edma_plat_ops
>   dmaengine: dw-edma: Create a new dw_edma_core_ops structure to
>     abstract controller operation
>   dmaengine: dw-edma: Add HDMA DebugFS support
> 
> v6->v7:
>   [1/5]
>   1.Update the commit log.
>   [2/5]
>   2.Revert dw_edma_core_handle_int back to dw-edma-core.h.
>   3.Fix code style.
>   [3/5]
>   4.Move the change of register file from patch[4/5] to patch[3/5].
>   5.Fix code style.
> 
> v6 link:
>   https://lore.kernel.org/lkml/20230310032342.17395-1-cai.huoqing@linux.dev/
> 
>  drivers/dma/dw-edma/Makefile                 |   8 +-
>  drivers/dma/dw-edma/dw-edma-core.c           |  86 ++----
>  drivers/dma/dw-edma/dw-edma-core.h           |  58 ++++
>  drivers/dma/dw-edma/dw-edma-pcie.c           |   4 +-
>  drivers/dma/dw-edma/dw-edma-v0-core.c        |  91 ++++--
>  drivers/dma/dw-edma/dw-edma-v0-core.h        |  14 +-
>  drivers/dma/dw-edma/dw-hdma-v0-core.c        | 277 +++++++++++++++++++
>  drivers/dma/dw-edma/dw-hdma-v0-core.h        |  17 ++
>  drivers/dma/dw-edma/dw-hdma-v0-debugfs.c     | 176 ++++++++++++
>  drivers/dma/dw-edma/dw-hdma-v0-debugfs.h     |  22 ++
>  drivers/dma/dw-edma/dw-hdma-v0-regs.h        | 130 +++++++++
>  drivers/pci/controller/dwc/pcie-designware.c |   2 +-
>  include/linux/dma/edma.h                     |   7 +-
>  13 files changed, 785 insertions(+), 107 deletions(-)
>  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.c
>  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-core.h
>  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.c
>  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-debugfs.h
>  create mode 100644 drivers/dma/dw-edma/dw-hdma-v0-regs.h
> 
> -- 
> 2.34.1
>