dmaengine: tegra-apb: Clean up suspend-resume

Browse source

It is enough to check whether hardware is busy on suspend and to reset
it across of suspend-resume because:

  1. Channel's configuration is fully re-programmed on each DMA
     transfer anyways.

  2. Context save-restore of an active channel won't end up well without
     pausing transfer prior to the context's saving, but note that every
     channel shall be idling at the time of suspend, so save-restore is
     not needed at all.

  3. The only case where context save-restore may be useful is when
     channel is in a paused state during suspend. But channel's pausing
     could be supported only on Tegra114+ and this functionality wasn't
     implemented by the driver for years now because there is no need for
     it in upstream kernel.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-14-digetx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

...

This commit is contained in:

Dmitry Osipenko 2020-02-09 19:33:50 +03:00 • committed by Vinod Koul

parent 84a3f375ee

commit dcb394b6b5

1 changed files with 69 additions and 67 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

134

drivers/dma/tegra20-apb-dma.c

View file