Re: [PATCH v11 0/8] Enable designware PCI EP EDMA locally

From: Bjorn Helgaas <helgaas@kernel.org>
To: Zhi Li <lznuaa@gmail.com>
Cc: "Serge Semin" <fancer.lancer@gmail.com>,
	"Vinod Koul" <vkoul@kernel.org>, "Frank Li" <Frank.Li@nxp.com>,
	"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
	hongxing.zhu@nxp.com, "Lucas Stach" <l.stach@pengutronix.de>,
	dl-linux-imx <linux-imx@nxp.com>,
	linux-pci@vger.kernel.org, dmaengine@vger.kernel.org,
	"Kishon Vijay Abraham I" <kishon@ti.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Serge Semin" <Sergey.Semin@baikalelectronics.ru>
Subject: Re: [PATCH v11 0/8] Enable designware PCI EP EDMA locally
Date: Mon, 23 May 2022 17:12:56 -0500	[thread overview]
Message-ID: <20220523221256.GA221421@bhelgaas> (raw)
In-Reply-To: <CAHrpEqR9dXg-4pRFA89ggv4CHXXwU-pWeTb082YRdCzmOTUjVQ@mail.gmail.com>

On Mon, May 23, 2022 at 01:41:48PM -0500, Zhi Li wrote:
> On Mon, May 23, 2022 at 1:02 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > On Mon, May 23, 2022 at 02:06:47PM +0300, Serge Semin wrote:
> > > Hello Vinod,
> > >
> > > On Tue, May 17, 2022 at 10:19:07AM -0500, Frank Li wrote:
> > > > Default Designware EDMA just probe remotely at host side.
> > > > This patch allow EDMA driver can probe at EP side.
> > > >
> > > > 1. Clean up patch
> > > >    dmaengine: dw-edma: Detach the private data and chip info structures
> > > >    dmaengine: dw-edma: Remove unused field irq in struct dw_edma_chip
> > > >    dmaengine: dw-edma: Change rg_region to reg_base in struct
> > > >    dmaengine: dw-edma: rename wr(rd)_ch_cnt to ll_wr(rd)_cnt in struct
> > > >
> > > > 2. Enhance EDMA driver to allow prode eDMA at EP side
> > > >    dmaengine: dw-edma: Add support for chip specific flags
> > > >    dmaengine: dw-edma: Add DW_EDMA_CHIP_32BIT_DBI for chip specific
> > > > flags (this patch removed at v11 because dma tree already have fixed
> > > > patch)
> > > >
> > > > 3. Bugs fix at EDMA driver when probe eDMA at EP side
> > > >    dmaengine: dw-edma: Fix programming the source & dest addresses for
> > > > ep
> > > >    dmaengine: dw-edma: Don't rely on the deprecated "direction" member
> > > >
> > > > 4. change pci-epf-test to use EDMA driver to transfer data.
> > > >    PCI: endpoint: Add embedded DMA controller test
> > > >
> > > > 5. Using imx8dxl to do test, but some EP functions still have not
> > > > upstream yet. So below patch show how probe eDMA driver at EP
> > > > controller driver.
> > > > https://lore.kernel.org/linux-pci/20220309120149.GB134091@thinkpad/T/#m979eb506c73ab3cfca2e7a43635ecdaec18d8097
> > >
> > > The series has been hanging out on review for over three months now.
> > > It has got to v11 and has been tested on at least two platforms. The
> > > original driver maintainer has been silent for all that time (most
> > > likely Gustavo dropped the driver maintaining role). Could you please
> > > merge it in seeing no comments have been posted for the last several
> > > weeks? The PCI Host/EP controller drivers maintainer suggested to get
> > > this series via the DMA-engine tree:
> > > https://lore.kernel.org/linux-pci/YnqlRShJzvma2SKM@lpieralisi/
> > > which is obviously right seeing it mainly concerns the DW eDMA driver.
> > > Though after that Lorenzo disappeared as quickly as popped up.)
> > >
> > > There is one more series depending on the changes in this
> > > patchset:
> > > https://lore.kernel.org/linux-pci/20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru/
> > > Me and Frank already settled all the conflicts and inter-dependencies,
> > > so at least his series is more than ready to be merged in into the
> > > kernel repo. It would be very good to get it accepted on this merge
> > > window so to have the kernel v5.19 with all this changes available.
> >
> > Since the v5.19 merge window is already open, it seems doubtful that
> > anybody would merge this so late in the cycle.
> >
> > If Gustavo isn't available or willing to merge it, it looks like Vinod
> > (maintainer of drivers/dma) would be the next logical candidate.
> 
> I think the last patch should not block other patches from merging.
> The last patch about pci-epf-test.c is totally independent from other patches.
> 
> I prefer to merge all the dma patches first.

Absolutely.  

Given an ack from Kishon, it would make sense for Vinod to merge them
all together since they're logically related, but I have no objection
to merging any of the drivers/dma patches separately.

Bjorn