Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210203155100.15034-1-cezary.rojewski@intel.com> <CAHp75VeuL0d48JBBQrb=twQvtwh4E_oB8Aszy+GtszhNWKqAmg@mail.gmail.com>
In-Reply-To: <CAHp75VeuL0d48JBBQrb=twQvtwh4E_oB8Aszy+GtszhNWKqAmg@mail.gmail.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Wed, 3 Feb 2021 19:08:49 +0200
Message-ID: <CAHp75Vc-By8mNzBoMqVSNac_yjX3J_Tv24pSxAw1FEFHTAwFLA@mail.gmail.com>
Subject: Re: [PATCH] Revert "dmaengine: dw: Enable runtime PM"
To:     Cezary Rojewski <cezary.rojewski@intel.com>
Cc:     dmaengine <dmaengine@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        viresh kumar <vireshk@kernel.org>,
        Vinod Koul <vkoul@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Feb 3, 2021 at 7:06 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Wed, Feb 3, 2021 at 5:53 PM Cezary Rojewski
> <cezary.rojewski@intel.com> wrote:
> >
> > This reverts commit 842067940a3e3fc008a60fee388e000219b32632.
> > For some solutions e.g. sound/soc/intel/catpt, DW DMA is part of a
> > compound device (in that very example, domains: ADSP, SSP0, SSP1, DMA0
> > and DMA1 are part of a single entity) rather than being a standalone
> > one. Driver for said device may enlist DMA to transfer data during
> > suspend or resume sequences.
> >
> > Manipulating RPM explicitly in dw's DMA request and release channel
> > functions causes suspend() to also invoke resume() for the exact same
> > device. Similar situation occurs for resume() sequence. Effectively
> > renders device dysfunctional after first suspend() attempt. Revert the
> > change to address the problem.
>
> I kinda had the mixed feelings about this, thanks for the report.

Side note: the better solution in general seems to have a specific
power domain for the ASoC multi-function devices (if ever you move to
use auxiliary bus, it may be done easier I think).

-- 
With Best Regards,
Andy Shevchenko