Linux kernel modifications for the Kernel Hacking exam
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Florian Fainelli eb73390ae2 ata: ahci_brcm: Recover from failures to identify devices
When powering up, the SATA controller may fail to mount the HDD. The SATA
controller will lock up, preventing it from negotiating to a lower speed or
transmitting data. Root cause is power supply noise creating resonance at 6 Ghz
and 3 GHz frequencies, which causes instability in the Clock-Data Recovery
(CDR) frontend module, resulting in false acquisition of the clock at SATA
6G/3G speeds.

The SATA controller may fail to mount the HDD and lock up, requiring a power
cycle. Broadcom chips suspected of being susceptible to this issue include
BCM7445, BCM7439, and BCM7366.

The Kernel implements an error recovery mechanism that resets the SATA PHY and
digital controller when the controller locks up. During this error recovery
process, typically there is less activity on the board and Broadcom STB chip,
so that the power supply is less noisy, thus allowing the SATA controller to
lock correctly.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-01-17 07:52:29 -08:00
arch Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-26 15:03:49 -08:00
block treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
certs
crypto Keys devel 2017-11-24 11:54:11 +11:00
Documentation Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
drivers ata: ahci_brcm: Recover from failures to identify devices 2018-01-17 07:52:29 -08:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
include Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:39:20 -08:00
init EXPERT Kconfig menu: fix broken EXPERT menu 2017-11-17 16:10:05 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
kernel Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:39:20 -08:00
lib Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
mm block/laptop_mode: Convert timers to use timer_setup() 2017-11-21 15:46:44 -08:00
net Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
samples kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
scripts Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
security Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
sound Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
tools Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
usr
virt Trimmed second batch of KVM changes for Linux 4.15 2017-11-24 19:44:25 -10:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap
COPYING
CREDITS
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig
MAINTAINERS RTC for 4.15 2017-11-22 20:58:23 -10:00
Makefile Linux 4.15-rc1 2017-11-26 16:01:47 -08:00
README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

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.