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Hans de Goede 181f4d2f44 pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare()
According to the data-sheet the way the PWM controller works is that
each input clock-cycle the base_unit gets added to a N bit counter and
that counter overflowing determines the PWM output frequency.

So assuming e.g. a 16 bit counter this means that if base_unit is set to 1,
after 65535 input clock-cycles the counter has been increased from 0 to
65535 and it will overflow on the next cycle, so it will overflow after
every 65536 clock cycles and thus the calculations done in
pwm_lpss_prepare() should use 65536 and not 65535.

This commit fixes this. Note this also aligns the calculations in
pwm_lpss_prepare() with those in pwm_lpss_get_state().

Note this effectively reverts commit 684309e504 ("pwm: lpss: Avoid
potential overflow of base_unit"). The next patch in this series really
fixes the potential overflow of the base_unit value.

Fixes: 684309e504 ("pwm: lpss: Avoid potential overflow of base_unit")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-4-hdegoede@redhat.com
2020-09-06 15:37:58 +02:00
arch Linux 5.8 2020-08-11 11:58:31 +10:00
block block-5.8-2020-07-10 2020-07-10 09:55:46 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto keys: asymmetric: fix error return code in software_key_query() 2020-07-15 15:49:04 -07:00
Documentation Linux 5.8 2020-08-11 11:58:31 +10:00
drivers pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare() 2020-09-06 15:37:58 +02:00
fs io_uring-5.8-2020-07-30 2020-07-30 09:47:07 -07:00
include drm/mst: Add support for QUERY_STREAM_ENCRYPTION_STATUS MST sideband message 2020-09-01 13:02:33 +05:30
init kbuild: fix CONFIG_CC_CAN_LINK(_STATIC) for cross-compilation with Clang 2020-07-02 00:57:45 +09:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-01 16:47:24 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-01 16:47:24 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm khugepaged: fix null-pointer dereference due to race 2020-07-24 12:42:41 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-01 16:47:24 -07:00
samples samples/vfs: avoid warning in statx override 2020-07-03 16:15:25 -07:00
scripts kbuild: remove redundant FORCE definition in scripts/Makefile.modpost 2020-08-02 23:09:16 +09:00
security integrity/ima: switch to using __kernel_read 2020-07-08 08:27:57 +02:00
sound sound fixes for 5.8-final or -rc8 2020-07-31 09:17:24 -07:00
tools Bugfixes and strengthening the validity checks on inputs from new userspace APIs. 2020-08-02 10:41:00 -07:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt kvm: use more precise cast and do not drop __user 2020-07-02 05:39:31 -04:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.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: Do not track defconfig from make savedefconfig 2020-07-05 16:15:46 +09:00
.mailmap mailmap: add entry for Mike Rapoport 2020-07-24 12:42:41 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
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 Linux 5.8 2020-08-11 11:58:31 +10:00
Makefile Linux 5.8 2020-08-02 14:21:45 -07:00
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.