The vendor driver unsets the set_iddig bit during power-on as well and
sets it when suspending the PHY. I did not notice this in the vendor
driver first, because it's part of the dwc_otg driver there (instead of
their PHY code). While here, also add all other REG_DBG_UART register
bit definitions.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-6-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Skip setting REG_ADP_BC_ACA_ENABLE on Meson8 SoCs and polling for the
REG_ADP_BC_ACA_PIN_FLOAT bit. The vendor also skips this part on Meson8
SoCs.
This fixes initialization of the host-only USB PHY on Meson8 which would
otherwise fail with "USB ID detect failed!".

Fixes: 4a3449d1 ("phy: meson8b-usb2: add support for the USB PHY on Meson8 SoCs")
Reported-by: Thomas Graichen <thomas.graichen@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-5-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Using a MMIO regmap and switch to regmap_update_bits() to simplify the
code in the driver. Also switch to devm_platform_ioremap_resource()
instead of open-coding it. No functional changes intended.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-4-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The USB2 PHY on Meson8m2 is identical to the one on Meson8b but
different to the one on Meson8. The only known difference is that Meson8
does not set the ACA_ENABLE bit while Meson8b and Meson8m2 do.
Add an explicit compatible string for Meson8m2 so those differences can
be taken care of.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200512222424.549351-3-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Now that we have the DT validation in place, let's convert the device
tree bindings for the Amlogic Meson8, Meson8b, Meson8m2 and GXBB USB2
PHY over to a YAML schema.

While here, also add the fallback compatible string
"amlogic,meson-gxbb-usb2-phy" which is already used in
arch/arm/boot/dts/meson{,8,8b}.dtsi.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-2-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The Intel eMMC PHY is only present on Intel Lightning Mountain SoCs.
Add an architecture dependency to the PHY_INTEL_EMMC config symbol, to
avoid asking the user about it when configuring a kernel for a non-x86
architecture.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200507113626.24026-3-geert+renesas@glider.beSigned-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Fix to return negative error code from some error handling
cases instead of 0, as done elsewhere in this function.

Fixes: 091876cc ("phy: ti: j721e-wiz: Add support for WIZ module present in TI J721E SoC")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/20200507054109.110849-1-weiyongjun1@huawei.comSigned-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Axe a clk that is unused in the driver.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20200507203127.202197-1-christophe.jaillet@wanadoo.frSigned-off-by: Kishon Vijay Abraham I <kishon@ti.com>

The USB phy takes some time to reset, so make sure we give it to it. The
delay length was taken from the 4x12 phy driver.

This manifested in issues with the DWC2 driver since commit fe369e18
("usb: dwc2: Make dwc2_readl/writel functions endianness-agnostic.")
where the endianness check would read the DWC ID as 0 due to the phy still
resetting, resulting in the wrong endian mode being chosen.
Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/BN6PR04MB06605D52502816E500683553A3D10@BN6PR04MB0660.namprd04.prod.outlook.comSigned-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Cadence SALVO PHY is a 28nm product, and is only used for USB3 & USB2.
According to the Cadence, this PHY is a legacy Module, and Sierra and
Torrent are later evolutions from it, and their sequence overlap is
minimal, meaning we cannot reuse either (Sierra & Torrent) of the PHY
drivers.
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Add Cadence SALVO PHY binding doc, this PHY is a legacy module,
and is only used for USB3 and USB2.
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Fix errors reported by dt_binding_check, due to missing required
regulators in the example node.

Fixes: f06b9fc9 ("dt-bindings: phy: Add binding for qcom,usb-snps-femto-v2")
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reported-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1588753589-22673-1-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

The UFS QMP v4 PHY has a largely different register set versus USB and
PCIe.  Rename the register offsets to denote that the value is specific for
the UFS PCS register.
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1588636467-23409-6-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

The register map for SM8150 QMP USB SSPHY has moved
QPHY_POWER_DOWN_CONTROL to a different offset.  Allow for
an offset in the register table to override default value
if it is a DP capable PHY.
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Link: https://lore.kernel.org/r/1588636467-23409-5-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add support for SM8150 QMP USB3 PHY with the necessary
initialization sequences as well as additional QMP V4
register definitions.
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Link: https://lore.kernel.org/r/1588636467-23409-4-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

This adds the SNPS FemtoPHY V2 driver used in QCOM SOCs.  There
are potentially multiple instances of this UTMI PHY on the
SOC, all which can utilize this driver.  The V2 driver will
have a different register map compared to V1.
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Philipp Zabel <pza@pengutronix.de>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/1588636467-23409-3-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

This binding shows the descriptions and properties for the
Synopsis Femto USB PHY V2 used on QCOM platforms.
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/1588636467-23409-2-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch adds the binding documentation for the HS/SS USB PHY found
inside Qualcom Dakota SoCs.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Link: https://lore.kernel.org/r/20200503201823.531757-2-robert.marko@sartura.hrSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add a driver to setup the USB PHY-s on Qualcom m IPQ40xx series SoCs.
The driver sets up HS and SS phys.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Link: https://lore.kernel.org/r/20200503201823.531757-1-robert.marko@sartura.hrSigned-off-by: Vinod Koul <vkoul@kernel.org>

The SM8250 UFS PHY can run off the same initialization sequence as
SM8150, but add the compatible to allow future changes.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

For DisplayPort use we need to set WIZ_CONFIG_LANECTL register's
P_STANDARD_MODE bits to "mode 3". In the DisplayPort use also the
P_ENABLE bits of the same register are set to P_ENABLE instead of
P_ENABLE_FORCE, so that the DisplayPort driver can enable and disable
the lane as needed. The DisplayPort mode is selected according to
"cdns,phy-type"-properties found in link subnodes under the managed
serdes (see "ti,sierra-phy-t0" and "ti,j721e-serdes-10g" devicetree
bindings for details). All other values of "cdns,phy-type"-property
but PHY_TYPE_DP will set P_STANDARD_MODE bits to 0 and P_ENABLE bits
to force enable.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This sorts the actual field names too, potentially causing even more
chaos and confusion at merge time if you have edited the MAINTAINERS
file.  But the end result is a more consistent layout, and hopefully
it's a one-time pain minimized by doing this just before the -rc1
release.

This was entirely scripted:

  ./scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS --order
Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

They are all supposed to be sorted, but people who add new entries don't
always know the alphabet.  Plus sometimes the entry names get edited,
and people don't then re-order the entry.

Let's see how painful this will be for merging purposes (the MAINTAINERS
file is often edited in various different trees), but Joe claims there's
relatively few patches in -next that touch this, and doing it just
before -rc1 is likely the best time.  Fingers crossed.

This was scripted with

  /scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS

but then I also ended up manually upper-casing a few entry names that
stood out when looking at the end result.
Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A set of three patches to fix the fallout of the newly added split
  lock detection feature.

  It addressed the case where a KVM guest triggers a split lock #AC and
  KVM reinjects it into the guest which is not prepared to handle it.

  Add proper sanity checks which prevent the unconditional injection
  into the guest and handles the #AC on the host side in the same way as
  user space detections are handled. Depending on the detection mode it
  either warns and disables detection for the task or kills the task if
  the mode is set to fatal"

* tag 'x86-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest
  KVM: x86: Emulate split-lock access as a write in emulator
  x86/split_lock: Provide handle_guest_split_lock()

Pull time(keeping) updates from Thomas Gleixner:

 - Fix the time_for_children symlink in /proc/$PID/ so it properly
   reflects that it part of the 'time' namespace

 - Add the missing userns limit for the allowed number of time
   namespaces, which was half defined but the actual array member was
   not added. This went unnoticed as the array has an exessive empty
   member at the end but introduced a user visible regression as the
   output was corrupted.

 - Prevent further silent ucount corruption by adding a BUILD_BUG_ON()
   to catch half updated data.

* tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ucount: Make sure ucounts in /proc/sys/user don't regress again
  time/namespace: Add max_time_namespaces ucount
  time/namespace: Fix time_for_children symlink

Pull scheduler fixes/updates from Thomas Gleixner:

 - Deduplicate the average computations in the scheduler core and the
   fair class code.

 - Fix a raise between runtime distribution and assignement which can
   cause exceeding the quota by up to 70%.

 - Prevent negative results in the imbalanace calculation

 - Remove a stale warning in the workqueue code which can be triggered
   since the call site was moved out of preempt disabled code. It's a
   false positive.

 - Deduplicate the print macros for procfs

 - Add the ucmap values to the SCHED_DEBUG procfs output for completness

* tag 'sched-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Add task uclamp values to SCHED_DEBUG procfs
  sched/debug: Factor out printing formats into common macros
  sched/debug: Remove redundant macro define
  sched/core: Remove unused rq::last_load_update_tick
  workqueue: Remove the warning in wq_worker_sleeping()
  sched/fair: Fix negative imbalance in imbalance calculation
  sched/fair: Fix race between runtime distribution and assignment
  sched/fair: Align rq->avg_idle and rq->avg_scan_cost

Pull perf fixes from Thomas Gleixner:
 "Three fixes/updates for perf:

   - Fix the perf event cgroup tracking which tries to track the cgroup
     even for disabled events.

   - Add Ice Lake server support for uncore events

   - Disable pagefaults when retrieving the physical address in the
     sampling code"

* tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Disable page faults when getting phys address
  perf/x86/intel/uncore: Add Ice Lake server uncore support
  perf/cgroup: Correct indirection in perf_less_group_idx()
  perf/core: Fix event cgroup tracking

Pull locking fixes from Thomas Gleixner:
 "Three small fixes/updates for the locking core code:

   - Plug a task struct reference leak in the percpu rswem
     implementation.

   - Document the refcount interaction with PID_MAX_LIMIT

   - Improve the 'invalid wait context' data dump in lockdep so it
     contains all information which is required to decode the problem"

* tag 'locking-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Improve 'invalid wait context' splat
  locking/refcount: Document interaction with PID_MAX_LIMIT
  locking/percpu-rwsem: Fix a task_struct refcount

Pull cifs fixes from Steve French:
 "Ten cifs/smb fixes:

   - five RDMA (smbdirect) related fixes

   - add experimental support for swap over SMB3 mounts

   - also a fix which improves performance of signed connections"

* tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: enable swap on SMB3 mounts
  smb3: change noisy error message to FYI
  smb3: smbdirect support can be configured by default
  cifs: smbd: Do not schedule work to send immediate packet on every receive
  cifs: smbd: Properly process errors on ib_post_send
  cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
  cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending
  cifs: smbd: Check send queue size before posting a send
  cifs: smbd: Merge code to track pending packets
  cifs: ignore cached share root handle closing errors

Pull NFS client bugfix from Trond Myklebust:
 "Fix an RCU read lock leakage in pnfs_alloc_ds_commits_list()"

* tag 'nfs-for-5.7-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  pNFS: Fix RCU lock leakage

Pull nios2 updates from Ley Foon Tan:

 - Remove nios2-dev@lists.rocketboards.org from MAINTAINERS

 - remove 'resetvalue' property

 - rename 'altr,gpio-bank-width' -> 'altr,ngpio'

 - enable the common clk subsystem on Nios2

* tag 'nios2-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  MAINTAINERS: Remove nios2-dev@lists.rocketboards.org
  arch: nios2: remove 'resetvalue' property
  arch: nios2: rename 'altr,gpio-bank-width' -> 'altr,ngpio'
  arch: nios2: Enable the common clk subsystem on Nios2

Pull dma-mapping fixes from Christoph Hellwig:

 - fix an integer truncation in dma_direct_get_required_mask
   (Kishon Vijay Abraham)

 - fix the display of dma mapping types (Grygorii Strashko)

* tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: fix displaying of dma allocation type
  dma-direct: fix data truncation in dma_direct_get_required_mask()

Pull more Kbuild updates from Masahiro Yamada:

 - raise minimum supported binutils version to 2.23

 - remove old CONFIG_AS_* macros that we know binutils >= 2.23 supports

 - move remaining CONFIG_AS_* tests to Kconfig from Makefile

 - enable -Wtautological-compare warnings to catch more issues

 - do not support GCC plugins for GCC <= 4.7

 - fix various breakages of 'make xconfig'

 - include the linker version used for linking the kernel into
   LINUX_COMPILER, which is used for the banner, and also exposed to
   /proc/version

 - link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y, which
   allows us to remove the lib-ksyms.o workaround, and to solve the last
   known issue of the LLVM linker

 - add dummy tools in scripts/dummy-tools/ to enable all compiler tests
   in Kconfig, which will be useful for distro maintainers

 - support the single switch, LLVM=1 to use Clang and all LLVM utilities
   instead of GCC and Binutils.

 - support LLVM_IAS=1 to enable the integrated assembler, which is still
   experimental

* tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (36 commits)
  kbuild: fix comment about missing include guard detection
  kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
  kbuild: replace AS=clang with LLVM_IAS=1
  kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
  kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y
  MIPS: fw: arc: add __weak to prom_meminit and prom_free_prom_memory
  kbuild: remove -I$(srctree)/tools/include from scripts/Makefile
  kbuild: do not pass $(KBUILD_CFLAGS) to scripts/mkcompile_h
  Documentation/llvm: fix the name of llvm-size
  kbuild: mkcompile_h: Include $LD version in /proc/version
  kconfig: qconf: Fix a few alignment issues
  kconfig: qconf: remove some old bogus TODOs
  kconfig: qconf: fix support for the split view mode
  kconfig: qconf: fix the content of the main widget
  kconfig: qconf: Change title for the item window
  kconfig: qconf: clean deprecated warnings
  gcc-plugins: drop support for GCC <= 4.7
  kbuild: Enable -Wtautological-compare
  x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2
  crypto: x86 - clean up poly1305-x86_64-cryptogams.S by 'make clean'
  ...

I do not longer work for credativ Germany.

Please, use my private email address instead.

This is for the case when people want to CC me on
patches sent from my old business email address.
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Another brown paper bag moment. pnfs_alloc_ds_commits_list() is leaking
the RCU lock.

Fixes: a9901899 ("pNFS: Add infrastructure for cleaning up per-layout commit structures")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Two types of #AC can be generated in Intel CPUs:
 1. legacy alignment check #AC
 2. split lock #AC

Reflect #AC back into the guest if the guest has legacy alignment checks
enabled or if split lock detection is disabled.

If the #AC is not a legacy one and split lock detection is enabled, then
invoke handle_guest_split_lock() which will either warn and disable split
lock detection for this task or force SIGBUS on it.

[ tglx: Switch it to handle_guest_split_lock() and rename the misnamed
  helper function. ]
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.176308876@linutronix.de

Emulate split-lock accesses as writes if split lock detection is on
to avoid #AC during emulation, which will result in a panic(). This
should never occur for a well-behaved guest, but a malicious guest can
manipulate the TLB to trigger emulation of a locked instruction[1].

More discussion can be found at [2][3].

[1] https://lkml.kernel.org/r/8c5b11c9-58df-38e7-a514-dc12d687b198@redhat.com
[2] https://lkml.kernel.org/r/20200131200134.GD18946@linux.intel.com
[3] https://lkml.kernel.org/r/20200227001117.GX9940@linux.intel.comSuggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.084300242@linutronix.de

Without at least minimal handling for split lock detection induced #AC,
VMX will just run into the same problem as the VMWare hypervisor, which
was reported by Kenneth.

It will inject the #AC blindly into the guest whether the guest is
prepared or not.

Provide a function for guest mode which acts depending on the host
SLD mode. If mode == sld_warn, treat it like user space, i.e. emit a
warning, disable SLD and mark the task accordingly. Otherwise force
SIGBUS.

 [ bp: Add a !CPU_SUP_INTEL stub for handle_guest_split_lock(). ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115516.978037132@linutronix.de
Link: https://lkml.kernel.org/r/20200402123258.895628824@linutronix.de

The keyword here is 'twice' to explain the trick.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>