korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-23 20:24:12 +08:00
Code Issues Packages Projects Releases Wiki Activity
1,224,674 Commits 113 Branches 5,292 Tags 3.5 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
35db7c9d01
Go to file
Matti Vaittinen 35db7c9d01 regulator: tps6287x: Force writing VSEL bit 
[ Upstream commit 1ace99d7c7 ]

The data-sheet for TPS6287x-Q1
https://www.ti.com/lit/ds/symlink/tps62873-q1.pdf
states at chapter 9.3.6.1 Output Voltage Range:

"Note that every change to the VRANGE[1:0] bits must be followed by a
write to the VSET register, even if the value of the VSET[7:0] bits does
not change."

The current implementation of the driver uses the
regulator_set_voltage_sel_pickable_regmap() helper which further uses
regmap_update_bits() to write the VSET-register. The
regmap_update_bits() will not access the hardware if the new register
value is same as old. It is worth noting that this is true also when the
register is marked volatile, which I can't say is wrong because
'read-mnodify-write'-cycle with a volatile register is in any case
something user should carefully consider.

The 'range_applied_by_vsel'-flag in regulator desc was added to force
the vsel register upodates by using regmap_write_bits(). This variant
will always unconditionally write the bits to the hardware.

It is worth noting that the vsel is now forced to be written to the
hardware, whether the range was changed or not. This may cause a
performance drop if users are wrtiting same voltage value repeteadly.

It would be possible to read the range register to determine if it was
changed, but this would be a performance issue for users who don't use
reg cache for vsel.

Always write the VSET register to the hardware regardless the cache.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 7b0518fbf2 ("regulator: Add support for TI TPS6287x regulators")
Link: https://msgid.link/r/ZktD50C5twF1EuKu@fedora
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:12:48 +02:00
arch x86/kconfig: Select ARCH_WANT_FRAME_POINTERS again when UNWINDER_FRAME_POINTER=y 2024-06-12 11:12:46 +02:00
block blk-cgroup: Properly propagate the iostat update up the hierarchy 2024-06-12 11:12:46 +02:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto KEYS: asymmetric: Add missing dependencies of FIPS_SIGNATURE_SELFTEST 2024-06-12 11:11:22 +02:00
Documentation dt-bindings: adc: axi-adc: add clocks property 2024-06-12 11:12:36 +02:00
drivers regulator: tps6287x: Force writing VSEL bit 2024-06-12 11:12:48 +02:00
fs nfs: keep server info for remounts 2024-06-12 11:12:47 +02:00
include regulator: pickable ranges: don't always cache vsel 2024-06-12 11:12:48 +02:00
init rust: make mutually exclusive with CFI_CLANG 2024-05-02 16:32:42 +02:00
io_uring io-wq: write next_work before dropping acct_lock 2024-06-12 11:11:33 +02:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel eventfs/tracing: Add callback for release of an eventfs_inode 2024-06-12 11:12:35 +02:00
lib lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure 2024-06-12 11:12:08 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/userfaultfd: Do not place zeropages when zeropages are disallowed 2024-06-12 11:11:33 +02:00
net rpcrdma: fix handling for RDMA_CM_EVENT_DEVICE_REMOVAL 2024-06-12 11:12:48 +02:00
rust rust: kernel: require Send for Module implementations 2024-05-17 12:01:56 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts s390/vdso: Create .build-id links for unstripped vdso files 2024-06-12 11:12:33 +02:00
security KEYS: trusted: Do not use WARN when encode fails 2024-05-25 16:22:55 +02:00
sound ASoC: tas2781: Fix wrong loading calibrated data sequence 2024-06-12 11:12:47 +02:00
tools selftests: net: kill smcrouted in the cleanup logic in amt.sh 2024-06-12 11:12:47 +02:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:28:18 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS pwm: Rename pwm_apply_state() to pwm_apply_might_sleep() 2024-06-12 11:12:24 +02:00
Makefile kbuild: unify vdso_install rules 2024-06-12 11:12:32 +02:00
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.