Re: [PATCH v3 0/2] dmaengine: qcom: bam_dma: Add "powered remotely" mode for BAM-DMUX

From: Bhupesh Sharma <bhupesh.sharma@linaro.org>
To: Stephan Gerhold <stephan@gerhold.net>
Cc: Vinod Koul <vkoul@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Andy Gross <agross@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	MSM <linux-arm-msm@vger.kernel.org>,
	dmaengine@vger.kernel.org,
	devicetree <devicetree@vger.kernel.org>,
	~postmarketos/upstreaming@lists.sr.ht
Subject: Re: [PATCH v3 0/2] dmaengine: qcom: bam_dma: Add "powered remotely" mode for BAM-DMUX
Date: Thu, 28 Oct 2021 12:20:35 +0530	[thread overview]
Message-ID: <CAH=2NtzfTqkwZum3owipC0kHvX2BMRssqRFmFAXPFkXK_SmN1w@mail.gmail.com> (raw)
In-Reply-To: <YXZL655lHukjar/x@gerhold.net>

Hi Stephan and Vinod,

On Mon, 25 Oct 2021 at 11:47, Stephan Gerhold <stephan@gerhold.net> wrote:
>
> On Mon, Oct 25, 2021 at 11:18:08AM +0530, Vinod Koul wrote:
> > On 18-10-21, 12:24, Stephan Gerhold wrote:
> > > The BAM Data Multiplexer (BAM-DMUX) provides access to the network data
> > > channels of modems integrated into many older Qualcomm SoCs, e.g.
> > > Qualcomm MSM8916 or MSM8974.
> > >
> > > Shortly said, BAM-DMUX is built using a simple protocol layer on top of
> > > a DMA engine (Qualcomm BAM DMA). For BAM-DMUX, the BAM DMA engine runs in
> > > a special mode where the modem/remote side is responsible for powering
> > > on the BAM when needed but we are responsible to initialize it.
> > > The BAM is powered off when unneeded by coordinating power control
> > > via bidirectional interrupts from the BAM-DMUX driver.
> > >
> > > This series adds one possible solution for handling the "powered remotely"
> > > mode in the bam_dma driver.
> >
> > This looks good me me. Bhupesh/Stephan what was the conclusion on the
> > the discussion you folks had?
> >
>
> Basically I said I would wait if you still want to take this for 5.16. :)
> There is a conflict with the DT schema conversion in Bhupesh's series,
> but it's trivial to solve no matter which of the patches is applied first.
>
> Since Bhupesh still needs to send v5 as far as I can tell (and has a
> much larger series overall), I think it's fine to apply this one first.
>
> Bhupesh, you can just copy-paste this below qcom,controlled-remotely
> in your DT schema if Vinod applies this patch first:
>
>   qcom,powered-remotely:
>     $ref: /schemas/types.yaml#/definitions/flag
>     description:
>       Indicates that the bam is powered up by a remote processor
>       but must be initialized by the local processor.

Sure, I can respin my v5 with 'qcom,powered-remotely' property added,
if this series gets applied first. Can I add you S-o-B to the same?

Thanks,
Bhupesh