dd69654cd3
Merge series from Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>: 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)
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.