From: Mark Brown Date: Mon, 8 May 2023 13:25:26 +0000 (+0900) Subject: spi: Add DMA mode support to spi-qcom-qspi X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dd69654cd32acad1a32d8e1c7b085a34db9d47e5;p=linux.git spi: Add DMA mode support to spi-qcom-qspi Merge series from Vijaya Krishna Nivarthi : 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 scenarios... Boot up and stabilise Suspend/Resume Sequence PIO DMA ======================= Boot-up 69088 19284 S/R 5066 3430 Speed test results... spi-nor read times in sec after 2 min uptime ============================================ PIO - Iterations-1000, min=3.18, max=3.74, avg=3.53 DMA - Iterations-1000, min=1.21, max=2.28, avg=1.79 spi-nor write times in sec after 2 min uptime ============================================= PIO - Iterations-1000, min=3.20, max=8.24, avg=3.58 DMA - Iterations-1000, min=1.25, max=5.13, avg=1.82 Further testing performed... a) multiple entries in sgt (simulated by max_dma_len = 1024) b) fallback to pio (simulated by dma setup failure) --- dd69654cd32acad1a32d8e1c7b085a34db9d47e5