Messages in this thread | | | Date | Wed, 22 Mar 2023 13:42:21 +0000 | Subject | Re: [PATCH v3] i2c: tegra: Share same DMA channel for RX and TX | From | Jon Hunter <> |
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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@nvidia.com> >> >> 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
-- nvpublic
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