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Badhri Jagan Sridharan 3287f58bcb usb: typec: tcpm: Wait for vbus discharge to VSAFE0V before toggling
When vbus auto discharge is enabled, TCPM can sometimes be faster than
the TCPC i.e. TCPM can go ahead and move the port to unattached state
(involves disabling vbus auto discharge) before TCPC could effectively
discharge vbus to VSAFE0V. This leaves vbus with residual charge and
increases the decay time which prevents tsafe0v from being met.
This change makes TCPM waits for a maximum of tSafe0V(max) for vbus
to discharge to VSAFE0V before transitioning to unattached state
and re-enable toggling. If vbus discharges to vsafe0v sooner, then,
transition to unattached state
happens right away.

Also, while in SNK_READY, when auto discharge is enabled, drive
disconnect based on vbus turning off instead of Rp disappearing on
CC pins. Rp disappearing on CC pins is almost instanteous compared
to vbus decay.

Sink detach:
[  541.703058] CC1: 3 -> 0, CC2: 0 -> 0 [state SNK_READY, polarity 0, disconnected]
[  541.703331] Setting voltage/current limit 5000 mV 0 mA
[  541.727235] VBUS on
[  541.749650] VBUS off
[  541.749653] pending state change SNK_READY -> SNK_UNATTACHED @ 650 ms [rev3 NONE_AMS]
[  541.749944] VBUS VSAFE0V
[  541.749945] state change SNK_READY -> SNK_UNATTACHED [rev3 NONE_AMS]
[  541.750806] Disable vbus discharge ret:0
[  541.907345] Start toggling
[  541.922799] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]

Source detach:
[ 2555.310414] state change SRC_SEND_CAPABILITIES -> SRC_READY [rev3 POWER_NEGOTIATION]
[ 2555.310675] AMS POWER_NEGOTIATION finished
[ 2555.310679] cc:=3
[ 2593.645886] CC1: 0 -> 0, CC2: 2 -> 0 [state SRC_READY, polarity 1, disconnected]
[ 2593.645919] pending state change SRC_READY -> SNK_UNATTACHED @ 650 ms [rev3 NONE_AMS]
[ 2593.648419] VBUS off
[ 2593.648960] VBUS VSAFE0V
[ 2593.648965] state change SRC_READY -> SNK_UNATTACHED [rev3 NONE_AMS]
[ 2593.649962] Disable vbus discharge ret:0
[ 2593.890322] Start toggling
[ 2593.925663] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0,

Fixes: f321a02cae ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20210225101104.1680697-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:37:15 +01:00
arch * Doc fixes 2021-03-04 11:26:17 -08:00
block block/bfq: update comments and default value in docs for fifo_expire 2021-03-02 11:25:38 -07:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto Keyrings miscellany 2021-02-23 16:09:23 -08:00
Documentation block-5.12-2021-03-05 2021-03-05 12:59:37 -08:00
drivers usb: typec: tcpm: Wait for vbus discharge to VSAFE0V before toggling 2021-03-10 09:37:15 +01:00
fs pstore fixes for v5.12-rc2 2021-03-05 17:21:25 -08:00
include block-5.12-2021-03-05 2021-03-05 12:59:37 -08:00
init kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO 2021-02-28 15:19:21 +09:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel io_uring-5.12-2021-03-05 2021-03-05 12:44:43 -08:00
lib Merge branch 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 2021-03-01 11:24:18 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
net io_uring-worker.v3-2021-02-25 2021-02-27 08:29:02 -08:00
samples treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
scripts gcc-plugins fixes for v5.12-rc2 2021-03-05 17:23:03 -08:00
security Keyrings miscellany 2021-02-23 16:09:23 -08:00
sound ALSA: hda/realtek: Apply dual codec quirks for MSI Godlike X570 board 2021-03-03 15:25:03 +01:00
tools * Doc fixes 2021-03-04 11:26:17 -08:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
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.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
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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 RISC-V Patches for the 5.12 Merge Window 2021-02-26 10:28:35 -08:00
Makefile Linux 5.12-rc2 2021-03-05 17:33:41 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.