From: Dmitry Osipenko <digetx@gmail.com>
To: "Jon Hunter" <jonathanh@nvidia.com>,
"Laxman Dewangan" <ldewangan@nvidia.com>,
"Vinod Koul" <vkoul@kernel.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 12/16] dmaengine: tegra-apb: Clean up suspend-resume
Date: Thu, 30 Jan 2020 19:08:57 +0300 [thread overview]
Message-ID: <394014f3-011a-d6b6-b5f2-f8c86834ec70@gmail.com> (raw)
In-Reply-To: <e787bee2-4b52-1643-b3a5-8c4e70f6fdca@nvidia.com>
30.01.2020 17:09, Jon Hunter пишет:
>
> On 30/01/2020 04:38, Dmitry Osipenko wrote:
>> It is enough to check whether hardware is busy on suspend and to reset
>> it across of suspend-resume because channel's configuration is fully
>> re-programmed on each DMA transaction anyways and because save-restore
>> of an active channel won't end up well without pausing transfer prior to
>> saving of the state (note that all channels shall be idling at the time of
>> suspend, so save-restore is not needed at all).
>
> I guess if we ever wanted to support SNDRV_PCM_INFO_PAUSE for audio and
> support the pause callback, then saving and restoring the channels could
> be needed. Right now I believe that it will just terminate_all transfers
> for audio on entering suspend. Any value in keeping this?
Indeed, looks like [1] pauses DMA during suspend if SNDRV_PCM_INFO_PAUSE
is supported.
[1]
https://elixir.bootlin.com/linux/v5.5/source/sound/core/pcm_dmaengine.c#L199
So we'll need to save-restore context only if DMA is in a paused state
during suspend, I'll adjust this patch to do that and will see if
enabling SNDRV_PCM_INFO_PAUSE works.
next prev parent reply other threads:[~2020-01-30 16:09 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-30 4:37 [PATCH v6 00/16] NVIDIA Tegra APB DMA driver fixes and improvements Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 01/16] dmaengine: tegra-apb: Fix use-after-free Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 02/16] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 03/16] dmaengine: tegra-apb: Implement synchronization hook Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 04/16] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 05/16] dmaengine: tegra-apb: Clean up tasklet releasing Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 06/16] dmaengine: tegra-apb: Use devm_platform_ioremap_resource Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 07/16] dmaengine: tegra-apb: Use devm_request_irq Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 08/16] dmaengine: tegra-apb: Fix coding style problems Dmitry Osipenko
2020-01-30 14:08 ` Jon Hunter
2020-01-30 4:37 ` [PATCH v6 09/16] dmaengine: tegra-apb: Remove unneeded initialization of tdc->config_init Dmitry Osipenko
2020-01-30 14:08 ` Jon Hunter
2020-01-30 4:37 ` [PATCH v6 10/16] dmaengine: tegra-apb: Remove assumptions about unavailable runtime PM Dmitry Osipenko
2020-01-30 14:09 ` Jon Hunter
2020-01-30 16:09 ` Dmitry Osipenko
2020-01-30 4:37 ` [PATCH v6 11/16] dmaengine: tegra-apb: Keep clock enabled only during of DMA transfer Dmitry Osipenko
2020-01-30 14:09 ` Jon Hunter
2020-01-30 16:11 ` Dmitry Osipenko
2020-01-30 18:45 ` Jon Hunter
2020-01-30 20:04 ` Dmitry Osipenko
2020-01-31 9:02 ` Jon Hunter
2020-01-31 14:22 ` Dmitry Osipenko
2020-02-01 15:13 ` Dmitry Osipenko
2020-02-03 11:37 ` Jon Hunter
2020-02-03 16:24 ` Dmitry Osipenko
2020-01-31 9:05 ` Jon Hunter
2020-01-30 4:38 ` [PATCH v6 12/16] dmaengine: tegra-apb: Clean up suspend-resume Dmitry Osipenko
2020-01-30 14:09 ` Jon Hunter
2020-01-30 16:08 ` Dmitry Osipenko [this message]
2020-01-30 18:06 ` Dmitry Osipenko
2020-01-30 18:26 ` Dmitry Osipenko
2020-01-30 18:58 ` Jon Hunter
2020-01-30 19:00 ` Jon Hunter
2020-01-30 20:06 ` Dmitry Osipenko
2020-01-30 4:38 ` [PATCH v6 13/16] dmaengine: tegra-apb: Add missing of_dma_controller_free Dmitry Osipenko
2020-01-30 4:38 ` [PATCH v6 14/16] dmaengine: tegra-apb: Allow to compile as a loadable kernel module Dmitry Osipenko
2020-01-30 4:38 ` [PATCH v6 15/16] dmaengine: tegra-apb: Remove MODULE_ALIAS Dmitry Osipenko
2020-01-30 4:38 ` [PATCH v6 16/16] dmaengine: tegra-apb: Support COMPILE_TEST Dmitry Osipenko
2020-01-30 14:10 ` Jon Hunter
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