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Serge Semin e5f4ca3fce usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend regression
First of all the commit e0082698b6 ("usb: dwc3: ulpi: conditionally
resume ULPI PHY") introduced the Suspend USB2.0 HS/FS/LS PHY regression,
as by design of the fix any attempt to read/write from/to the PHY control
registers will completely disable the PHY suspension, which consequently
will increase the USB bus power consumption. Secondly the fix won't work
well for the very first attempt of the ULPI PHY control registers IO,
because after disabling the USB2.0 PHY suspension functionality it will
still take some time for the bus to resume from the sleep state if one has
been reached before it. So the very first PHY register read/write
operation will take more time than the busy-loop provides and the IO
timeout error might be returned anyway.

Here we suggest to fix the denoted problems in the following way. First of
all let's not disable the Suspend USB2.0 HS/FS/LS PHY functionality so to
make the controller and the USB2.0 bus more power efficient. Secondly
instead of that we'll extend the PHY IO op wait procedure with 1 - 1.2 ms
sleep if the PHY suspension is enabled (1ms should be enough as by LPM
specification it is at most how long it takes for the USB2.0 bus to resume
from L1 (Sleep) state). Finally in case if the USB2.0 PHY suspension
functionality has been disabled on the DWC USB3 controller setup procedure
we'll compensate the USB bus resume process latency by extending the
busy-loop attempts counter.

Fixes: e0082698b6 ("usb: dwc3: ulpi: conditionally resume ULPI PHY")
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201210085008.13264-4-Sergey.Semin@baikalelectronics.ru
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28 15:55:44 +01:00
Documentation dt-bindings: usb: Add new compatible string for AM64 SoC 2020-12-28 15:40:47 +01:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch RISC-V Fixes for 5.11-rc1 2020-12-24 14:05:05 -08:00
block block: update some copyrights 2020-12-22 08:43:06 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: aegis128 - avoid spurious references crypto_aegis128_update_simd 2020-12-04 18:16:53 +11:00
drivers usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend regression 2020-12-28 15:55:44 +01:00
fs proc mountinfo: make splice available again 2020-12-27 12:00:36 -08:00
include Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-12-25 10:54:29 -08:00
init kasan, arm64: only use kasan_depth for software modes 2020-12-22 12:55:07 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel Misc fixes/updates: 2020-12-27 09:06:10 -08:00
lib kasan: introduce CONFIG_KASAN_HW_TAGS 2020-12-22 12:55:07 -08:00
mm virtio,vdpa: features, cleanups, fixes 2020-12-24 12:06:46 -08:00
net 9p for 5.11-rc1 2020-12-21 10:28:02 -08:00
samples ARM: SoC drivers for v5.11 2020-12-16 16:38:41 -08:00
scripts Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux 2020-12-25 11:05:32 -08:00
security Provide a fix for the incorrect handling of privilege 2020-12-24 14:08:43 -08:00
sound sound fixes for 5.11-rc1 2020-12-23 15:11:08 -08:00
tools Fix a segfault that occurs when built with Clang. 2020-12-27 09:08:23 -08:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt ARM: 2020-12-20 10:44:05 -08:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap RDMA 5.11 pull request 2020-12-16 13:42:26 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-11 22:29:38 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update address for Cadence USB3 driver 2020-12-28 15:40:08 +01:00
Makefile Linux 5.11-rc1 2020-12-27 15:30:22 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.