mainlining shenanigans
5ea47691bd
Setting max_blk_count to 1 here was causing the mmc block layer
to always use the MMC_READ_SINGLE_BLOCK command here, which the
driver does not DMA-accelerate.
Drop the max_blk_ settings here. The mmc host defaults suffice,
along with the max_segs and max_seg_size settings, which I have
now documented in more detail.
Now each MMC command reads 4 512-byte blocks, using DMA instead of
PIO. On my SD card, this increases read performance (measured with dd)
from 167kb/sec to 4.6mb/sec.
Link: http://lkml.kernel.org/r/CAD8Lp47L5T3jnAjBiPs1cQ+yFA3L6LJtgFvMETnBrY63-Zdi2g@mail.gmail.com
Signed-off-by: Daniel Drake <drake@endlessm.com>
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.