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Date:   Tue, 25 Oct 2022 23:50:02 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     Serge Semin <Sergey.Semin@baikalelectronics.ru>,
        Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>, Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Jingoo Han <jingoohan1@gmail.com>, Frank Li <Frank.Li@nxp.com>,
        Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
        Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        linux-pci@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-kernel@vger.kernel.org, Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH RESEND v5 00/24] dmaengine: dw-edma: Add RP/EP local DMA
 controllers support
Message-ID: <20221025205002.u3kznrq7hdp4shnm@mobilestation>
References: <20220822185332.26149-1-Sergey.Semin@baikalelectronics.ru>
 <20221025075930.GB221610@thinkpad>
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On Tue, Oct 25, 2022 at 01:29:30PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Aug 22, 2022 at 09:53:08PM +0300, Serge Semin wrote:
> > This is a final patchset in the series created in the framework of
> > my Baikal-T1 PCIe/eDMA-related work:
> > 
> > [1: Done v5] PCI: dwc: Various fixes and cleanups
> > Link: https://lore.kernel.org/linux-pci/20220624143428.8334-1-Sergey.Semin@baikalelectronics.ru/
> > Merged: kernel 6.0-rc1
> > [2: Done v4] PCI: dwc: Add hw version and dma-ranges support
> > Link: https://lore.kernel.org/linux-pci/20220624143947.8991-1-Sergey.Semin@baikalelectronics.ru
> > Merged: kernel 6.0-rc1
> > [3: In-review v5] PCI: dwc: Add generic resources and Baikal-T1 support
> > Link: https://lore.kernel.org/linux-pci/20220822184701.25246-1-Sergey.Semin@baikalelectronics.ru/
> > [4: Done v5] dmaengine: dw-edma: Add RP/EP local DMA support
> > Link: ---you are looking at it---
> > 
> > Note it is very recommended to merge the patchsets in the same order as
> > they are listed in the set above in order to have them applied smoothly.
> > Nothing prevents them from being reviewed synchronously though.
> > 
> > Please note originally this series was self content, but due to Frank
> > being a bit faster in his work submission I had to rebase my patchset onto
> > his one. So now this patchset turns to be dependent on the Frank' work:
> > 
> > Link: https://lore.kernel.org/linux-pci/20220524152159.2370739-1-Frank.Li@nxp.com/
> > 
> > Here is a short summary regarding this patchset. The series starts with
> > fixes patches. We discovered that the dw-edma-pcie.c driver incorrectly
> > initializes the LL/DT base addresses for the platforms with not matching
> > CPU and PCIe memory spaces. It is fixed by using the pci_bus_address()
> > method to get a correct base address. After that you can find a series of
> > the interleaved xfers fixes. It turned out the interleaved transfers
> > implementation didn't work quite correctly from the very beginning for
> > instance missing src/dst addresses initialization, etc. In the framework
> > of the next two patches we suggest to add a new platform-specific
> > callback - pci_address() and use it to convert the CPU address to the PCIe
> > space address. It is at least required for the DW eDMA remote End-point
> > setup on the platforms with not-matching CPU/PCIe address spaces. In case
> > of the DW eDMA local RP/EP setup the conversion will be done automatically
> > by the outbound iATU (if no DMA-bypass flag is specified for the
> > corresponding iATU window). Then we introduce a set of the patches to make
> > the DebugFS part of the code supporting the multi-eDMA controllers
> > platforms. It starts with several cleanup patches and is closed joining
> > the Read/Write channels into a single DMA-device as they originally should
> > have been. After that you can find the patches with adding the non-atomic
> > io-64 methods usage, dropping DT-region descriptors allocation, replacing
> > chip IDs with the device name. In addition to that in order to have the
> > eDMA embedded into the DW PCIe RP/EP supported we need to bypass the
> > dma-ranges-based memory ranges mapping since in case of the root port DT
> > node it's applicable for the peripheral PCIe devices only. Finally at the
> > series closure we introduce a generic DW eDMA controller support being
> > available in the DW PCIe Root Port/Endpoint driver.
> > 
> 

> Looks like this series still got stuck :( And most of the discussion is with
> patch 22/24 and it is for the Baikal platform (at present) I believe. There is
> also a discussion on 24/24, but that's not a big deal as 22/24.
> 
> Can we exclude the patch 22/24 (even 24/24 if required) and merge rest in the
> meantime. The patch(es) can still be submitted separately and merged after
> reaching consensus.

The discussion has come to some conclusion in the framework of another
series:
https://lore.kernel.org/linux-pci/20221007224515.sseyabdfa2phcsdz@mobilestation/
It includes solutions for several problems raised by @Robin Murphy.
Seeing no objection from @Robin received and the solutions were mainly
suggested by @Robin himself I'll implement them in the next series
re-spin. So to speak don't worry. The series isn't stuck. I'll
resubmit it for review on this week.

-Sergey

> 
> Thanks,
> Mani
> 
> > Link: https://lore.kernel.org/linux-pci/20220324014836.19149-1-Sergey.Semin@baikalelectronics.ru/
> > Changelog v2:
> > - Drop the patches:
> >   [PATCH 1/25] dmaengine: dw-edma: Drop dma_slave_config.direction field usage
> >   [PATCH 2/25] dmaengine: dw-edma: Fix eDMA Rd/Wr-channels and DMA-direction semantics
> >   since they are going to be merged in in the framework of the
> >   Frank's patchset.
> > - Add a new patch: "dmaengine: dw-edma: Release requested IRQs on
> >   failure."
> > - Drop __iomem qualifier from the struct dw_edma_debugfs_entry instance
> >   definition in the dw_edma_debugfs_u32_get() method. (@Manivannan)
> > - Add a new patch: "dmaengine: dw-edma: Rename DebugFS dentry variables to
> >   'dent'." (@Manivannan)
> > - Slightly extend the eDMA name array size. (@Manivannan)
> > - Change the specific DMA mapping comment a bit to being
> >   clearer. (@Manivannan)
> > - Add a new patch: "PCI: dwc: Add generic iATU/eDMA CSRs space detection
> >   method."
> > - Don't fail eDMA detection procedure if the DW eDMA driver couldn't probe
> >   device. That happens if the driver is disabled. (@Manivannan)
> > - Add "dma" registers resource mapping procedure. (@Manivannan)
> > - Move the eDMA CSRs space detection into the dw_pcie_map_detect() method.
> > - Remove eDMA on the dw_pcie_ep_init() internal errors. (@Manivannan)
> > - Remove eDMA in the dw_pcie_ep_exit() method.
> > - Move the dw_pcie_edma_detect() method execution to the tail of the
> >   dw_pcie_ep_init() function.
> > 
> > Link: https://lore.kernel.org/linux-pci/20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru/
> > Changelog v3:
> > - Conditionally set dchan->dev->device.dma_coherent field since it can
> >   be missing on some platforms. (@Manivannan)
> > - Drop the patch: "PCI: dwc: Add generic iATU/eDMA CSRs space detection
> >   method". A similar modification has been done in another patchset.
> > - Add more comprehensive and less regression prune eDMA block detection
> >   procedure.
> > - Drop the patch: "dma-direct: take dma-ranges/offsets into account in
> >   resource mapping". It will be separately reviewed.
> > - Remove Manivannan tb tag from the modified patches.
> > - Rebase onto the kernel v5.18.
> > 
> > Link: https://lore.kernel.org/linux-pci/20220610091459.17612-1-Sergey.Semin@baikalelectronics.ru
> > Changelog v4:
> > - Rabase onto the laters Frank Li series:
> > Link: https://lore.kernel.org/all/20220524152159.2370739-1-Frank.Li@nxp.com/
> > - Add Vinod' Ab-tag.
> > - Rebase onto the kernel v5.19-rcX.
> > 
> > Link: https://lore.kernel.org/linux-pci/20220728142841.12305-1-Sergey.Semin@baikalelectronics.ru
> > Changelog v5:
> > - Just resend.
> > - Rebase onto the kernel v6.0-rc2.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Acked-By: Vinod Koul <vkoul@kernel.org>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
> > Cc: "Krzysztof Wilczyński" <kw@linux.com>
> > Cc: linux-pci@vger.kernel.org
> > Cc: dmaengine@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > 
> > Serge Semin (24):
> >   dmaengine: Fix dma_slave_config.dst_addr description
> >   dmaengine: dw-edma: Release requested IRQs on failure
> >   dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address
> >   dmaengine: dw-edma: Fix missing src/dst address of the interleaved
> >     xfers
> >   dmaengine: dw-edma: Don't permit non-inc interleaved xfers
> >   dmaengine: dw-edma: Fix invalid interleaved xfers semantics
> >   dmaengine: dw-edma: Add CPU to PCIe bus address translation
> >   dmaengine: dw-edma: Add PCIe bus address getter to the remote EP
> >     glue-driver
> >   dmaengine: dw-edma: Drop chancnt initialization
> >   dmaengine: dw-edma: Fix DebugFS reg entry type
> >   dmaengine: dw-edma: Stop checking debugfs_create_*() return value
> >   dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor
> >   dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated
> >   dmaengine: dw-edma: Rename DebugFS dentry variables to 'dent'
> >   dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure
> >   dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor
> >   dmaengine: dw-edma: Join Write/Read channels into a single device
> >   dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory
> >   dmaengine: dw-edma: Use non-atomic io-64 methods
> >   dmaengine: dw-edma: Drop DT-region allocation
> >   dmaengine: dw-edma: Replace chip ID number with device name
> >   dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup
> >   dmaengine: dw-edma: Skip cleanup procedure if no private data found
> >   PCI: dwc: Add DW eDMA engine support
> > 
> >  drivers/dma/dw-edma/dw-edma-core.c            | 216 +++++-----
> >  drivers/dma/dw-edma/dw-edma-core.h            |  10 +-
> >  drivers/dma/dw-edma/dw-edma-pcie.c            |  24 +-
> >  drivers/dma/dw-edma/dw-edma-v0-core.c         |  60 +--
> >  drivers/dma/dw-edma/dw-edma-v0-core.h         |   1 -
> >  drivers/dma/dw-edma/dw-edma-v0-debugfs.c      | 372 ++++++++----------
> >  drivers/dma/dw-edma/dw-edma-v0-debugfs.h      |   5 -
> >  .../pci/controller/dwc/pcie-designware-ep.c   |  12 +-
> >  .../pci/controller/dwc/pcie-designware-host.c |  13 +-
> >  drivers/pci/controller/dwc/pcie-designware.c  | 186 +++++++++
> >  drivers/pci/controller/dwc/pcie-designware.h  |  20 +
> >  include/linux/dma/edma.h                      |  18 +-
> >  include/linux/dmaengine.h                     |   2 +-
> >  13 files changed, 583 insertions(+), 356 deletions(-)
> > 
> > -- 
> > 2.35.1
> > 
> 
> -- 
> மணிவண்ணன் சதாசிவம்