On 22/03/2023 12:00, Akhil R wrote:
On 22/03/2023 10:24, Akhil R wrote:
Allocate only one DMA channel for I2C and share it for both TX and RX
instead of using two different DMA hardware channels with the same
slave ID. Since I2C supports only half duplex, there is no impact on
perf with this.
Signed-off-by: Akhil R <akhilrajeev@xxxxxxxxxx>
Just to confirm. This impacts all Tegra devices from Tegra20 to the
latest. Does this work for all Tegra and the different DMA controllers
that they have?
Yes, It should. I could see in the APB DMA driver that the same channel
could be used for TX and RX and the direction is configured only during
dma_prep_*() calls.
I did not test it on a Tegra with APB DMA, but since it works very similar
to GPC DMA there should not be any impact.
OK. BTW, this does not apply cleanly on top of -next. It appears that
this is based on top "i2c: tegra: Fix PEC support for SMBUS block read"
and that one needs to be applied first. This can be avoided if you send
as a series.
Jon
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nvpublic
