From: Vinod <vkoul@kernel.org>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: dmaengine@vger.kernel.org, alsa-devel@alsa-project.org,
linux-kernel@vger.kernel.org,
Dan Williams <dan.j.williams@intel.com>,
Lars-Peter Clausen <lars@metafoo.de>,
Mark Brown <broonie@kernel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH] dma: add support for reporting pause and resume separately
Date: Mon, 9 Jul 2018 22:59:37 +0530 [thread overview]
Message-ID: <20180709172937.GP22377@vkoul-mobl> (raw)
In-Reply-To: <20180702130819eucas1p2e11d8fabec93ba78d9e84f4ca6e5fd65~9jzNWZMqQ1216712167eucas1p27@eucas1p2.samsung.com>
On 02-07-18, 15:08, Marek Szyprowski wrote:
> 'cmd_pause' DMA channel capability means that respective DMA engine
> supports both pausing and resuming given DMA channel. However, in some
> cases it is important to know if DMA channel can be paused without the
> need to resume it. This is a typical requirement for proper residue
> reading on transfer timeout in UART drivers. There are also some DMA
> engines with limited hardware, which doesn't really support resuming.
>
> Reporting pause and resume capabilities separately allows UART drivers to
> properly check for the really required capabilities and operate in DMA
> mode also in systems with limited DMA hardware. On the other hand drivers,
> which rely on full channel suspend/resume support, should now check for
> both 'pause' and 'resume' features.
>
> Existing clients of dma_get_slave_caps() have been checked and the only
> driver which rely on proper channel resuming is soc-generic-dmaengine-pcm
> driver, which has been updated to check the newly added capability.
> Existing 'cmd_pause' now only indicates that DMA engine support pausing
> given DMA channel.
Applied after fixing the subsystem name, thanks
--
~Vinod
prev parent reply other threads:[~2018-07-09 17:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180702130819eucas1p2e11d8fabec93ba78d9e84f4ca6e5fd65@eucas1p2.samsung.com>
2018-07-02 13:08 ` [PATCH] dma: add support for reporting pause and resume separately Marek Szyprowski
2018-07-04 7:00 ` Vinod
2018-07-04 10:38 ` Andy Shevchenko
2018-07-06 6:00 ` Vinod
2018-07-06 6:22 ` Marek Szyprowski
2018-07-09 11:17 ` Mark Brown
2018-07-09 17:29 ` Vinod [this message]
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