[PATCH] [3.3] ARM: tegra: use APB DMA for accessing APB devices
swarren at nvidia.com
Tue Oct 18 15:28:57 EDT 2011
Olof Johansson wrote at Tuesday, October 18, 2011 1:12 PM:
> Also, I can't imagine a case where CONFIG_TEGRA_SYSTEM_DMA makes sense
> to keep off. Can you? If so, I'm tempted to just kill it (in a
> separate patch).
I wondered about that too when I first saw that config option.
Still, I don't think it's impossible to have a system where the DMA driver
isn't useful; looking across a few kernels, I see it being used for:
* Audio; I2S and SPDIF, not HD-audio
* SPI (master and slave)
* The tegra_hsuart driver (not sure what benefit that has over 8250.c...)
* This APB/fuse/DMA workaround
All of which seem optional given the fourth one isn't required if DMA
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