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Manivannan Sadhasivam 556e404691 scsi: ufs: qcom: Add a readl() to make sure ref_clk gets enabled
commit 8eecddfca3 upstream.

In ufs_qcom_dev_ref_clk_ctrl(), it was noted that the ref_clk needs to be
stable for at least 1us. Even though there is wmb() to make sure the write
gets "completed", there is no guarantee that the write actually reached the
UFS device. There is a good chance that the write could be stored in a
Write Buffer (WB). In that case, even though the CPU waits for 1us, the
ref_clk might not be stable for that period.

So lets do a readl() to make sure that the previous write has reached the
UFS device before udelay().

Also, the wmb() after writel_relaxed() is not really needed. Both writel()
and readl() are ordered on all architectures and the CPU won't speculate
instructions after readl() due to the in-built control dependency with read
value on weakly ordered architectures. So it can be safely removed.

Link: https://lore.kernel.org/r/20220504084212.11605-4-manivannan.sadhasivam@linaro.org
Fixes: f06fcc7155 ("scsi: ufs-qcom: add QUniPro hardware support and power optimizations")
Cc: stable@vger.kernel.org
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:21:24 +02:00
arch s390/perf: obtain sie_block from the right address 2022-06-09 10:21:24 +02:00
block bfq: Track whether bfq_group is still online 2022-06-09 10:21:22 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: cryptd - Protect per-CPU resource by disabling BH. 2022-06-09 10:21:17 +02:00
Documentation spi: qcom-qspi: Add minItems to interconnect-names 2022-06-09 10:20:59 +02:00
drivers scsi: ufs: qcom: Add a readl() to make sure ref_clk gets enabled 2022-06-09 10:21:24 +02:00
fs ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock 2022-06-09 10:21:24 +02:00
include mailbox: forward the hrtimer if not queued and under a lock 2022-06-09 10:21:18 +02:00
init random: handle latent entropy and command line from random_init() 2022-05-30 09:33:44 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:21:17 +02:00
kernel tracing: Fix potential double free in create_var_ref() 2022-06-09 10:21:23 +02:00
lib lib/crypto: add prompts back to crypto libraries 2022-06-06 08:42:42 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm, compaction: fast_find_migrateblock() should return pfn in the target zone 2022-06-09 10:21:23 +02:00
net wifi: mac80211: fix use-after-free in chanctx code 2022-06-09 10:21:22 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:40:21 +02:00
scripts scripts/faddr2line: Fix overlapping text section failures 2022-06-09 10:21:08 +02:00
security efi: Do not import certificates from UEFI Secure Boot for T2 Macs 2022-06-09 10:21:22 +02:00
sound ASoC: atmel-classd: Remove endianness flag on class d component 2022-06-09 10:21:16 +02:00
tools perf jevents: Fix event syntax error caused by ExtSel 2022-06-09 10:21:21 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.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 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 MAINTAINERS: add git tree for random.c 2022-05-30 09:33:24 +02:00
Makefile Linux 5.10.120 2022-06-06 08:42:45 +02:00
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.