Re: [PATCH 0/2] spi: Add DMA mode support to spi-qcom-qspi

[Vijaya Krishna Nivarthi]

Thank you for the review...


On 4/5/2023 2:00 AM, Stephen Boyd wrote:
> Quoting Vijaya Krishna Nivarthi (2023-04-04 11:03:18)
> > There are large number of QSPI irqs that fire during boot/init and later
> > on every suspend/resume.
> > This could be made faster by doing DMA instead of PIO.
> > Below is comparison for number of interrupts raised in 2 acenarios...
> > Boot up and stabilise
> > Suspend/Resume
> >
> > Sequence   PIO    DMA
> > =======================
> > Boot-up    69088  19284
> > S/R        5066   3430
> The interrupts are less, yes, but does it save time or power?

We have not made measurements but the change is expected to improve 
performance.

Testing revealed no regressions.