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Luca Ceresoli bdc16fe9df clk: vc5: fix output disabling when enabling a FOD
[ Upstream commit fc336ae622 ]

On 5P49V6965, when an output is enabled we enable the corresponding
FOD. When this happens for the first time, and specifically when writing
register VC5_OUT_DIV_CONTROL in vc5_clk_out_prepare(), all other outputs
are stopped for a short time and then restarted.

According to Renesas support this is intended: "The reason for that is VC6E
has synced up all output function".

This behaviour can be disabled at least on VersaClock 6E devices, of which
only the 5P49V6965 is currently implemented by this driver. This requires
writing bit 7 (bypass_sync{1..4}) in register 0x20..0x50.  Those registers
are named "Unused Factory Reserved Register", and the bits are documented
as "Skip VDDO<N> verification", which does not clearly explain the relation
to FOD sync. However according to Renesas support as well as my testing
setting this bit does prevent disabling of all clock outputs when enabling
a FOD.

See "VersaClock ® 6E Family Register Descriptions and Programming Guide"
(August 30, 2018), Table 116 "Power Up VDD check", page 58:
https://www.renesas.com/us/en/document/mau/versaclock-6e-family-register-descriptions-and-programming-guide

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/20210527211647.1520720-1-luca@lucaceresoli.net
Fixes: 2bda748e6a ("clk: vc5: Add support for IDT VersaClock 5P49V6965")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:19 +02:00
arch x86/sev: Split up runtime #VC handler for correct state tracking 2021-07-14 16:56:09 +02:00
block blk-mq: update hctx->dispatch_busy in case of real scheduler 2021-07-14 16:56:13 +02:00
certs certs: Add ability to preload revocation certs 2021-06-30 08:47:30 -04:00
crypto crypto: sm2 - fix a memory leak in sm2 2021-07-14 16:56:06 +02:00
Documentation mm/debug_vm_pgtable/basic: add validation for dirtiness after write protect 2021-07-14 16:56:13 +02:00
drivers clk: vc5: fix output disabling when enabling a FOD 2021-07-14 16:56:19 +02:00
fs dax: fix ENOMEM handling in grab_mapping_entry() 2021-07-14 16:56:13 +02:00
include net/sched: act_vlan: Fix modify to allow 0 2021-07-14 16:56:19 +02:00
init sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
ipc ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry 2021-05-26 12:06:54 +02:00
kernel psi: Fix race between psi_trigger_create/destroy 2021-07-14 16:56:10 +02:00
lib lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING 2021-07-14 16:56:10 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/page_alloc: fix counting of managed_pages 2021-07-14 16:56:14 +02:00
net net/sched: act_vlan: Fix modify to allow 0 2021-07-14 16:56:19 +02:00
samples samples: vfio-mdev: fix error handing in mdpy_fb_probe() 2021-06-10 13:39:15 +02:00
scripts kbuild: Fix objtool dependency for 'OBJECT_FILES_NON_STANDARD_<obj> := n' 2021-07-14 16:56:04 +02:00
security evm: fix writing <securityfs>/evm overflow 2021-07-14 16:56:04 +02:00
sound ALSA: hda/realtek: fix mute/micmute LEDs for HP EliteBook 830 G8 Notebook PC 2021-07-14 16:55:37 +02:00
tools selftests/lkdtm: Avoid needing explicit sub-shell 2021-07-14 16:55:38 +02:00
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 KVM: do not allow mapping valid but non-reference-counted pages 2021-06-30 08:47:25 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
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 f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile Makefile: fix GDB warning with CONFIG_RELR 2021-07-14 16:55:53 +02:00
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Linux kernel
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