mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-06 08:47:44 -04:00
ef6b75671b
Cadence sent out an errata report to their customers of this IP. This errata is not so severe, but the tune request should be sent twice to avoid the potential issue. Quote from the report: Problem Summary --------------- The IP6116 SD/eMMC PHY design has a timing issue on receive data path. This issue may lead to an incorrect values of read/write pointers of the synchronization FIFO. Such a situation can happen at the SDR104 and HS200 tuning procedure when the PHY is requested to change a phase of sampling clock when moving to the next tuning iteration. Workarounds ----------- The following are valid workarounds to resolve the issue: 1. In eMMC mode, software sends tune request twice instead of once at each iteration. This means that the clock phase is not changed on the second request so there is no potential for clock instability. 2. In SD mode, software must not use the hardware tuning and instead perform an almost identical procedure to eMMC, using the HRS34 Tune Force register. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.