According to the UFS Spec, the Flags field in the UPIU is one byte in size,
not 4. Change it to be u8.

Link: https://lore.kernel.org/r/20200706123936.24799-1-huobean@gmail.comTested-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The "head" pointer can't be NULL because it points to an address in the
middle of a ufs_hba struct.  Looking at this code, probably someone would
wonder if the intent was to check whether "hba" is NULL, but "hba" isn't
NULL and the check can just be removed.

Link: https://lore.kernel.org/r/20200626105133.GF314359@mwandaAcked-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If a UFS device is not qualified to use WriteBooster, either due to wrong
UFS version or device-specific quirks, then the capability in host shall be
disabled to prevent any WriteBooster operations in the future.

Link: https://lore.kernel.org/r/20200625030430.25048-1-stanley.chu@mediatek.com
Fixes: 3d17b9b5 ("scsi: ufs: Add write booster feature support")
Tested-by: NSteev Klimaszewski <steev@kali.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

While building for x86_64 allmodconfig, the following warning was reported:

WARNING: modpost: missing MODULE_LICENSE() in drivers/scsi/ufs/ufs-exynos.o

Add the missing license/author/description tags.

Link: https://lore.kernel.org/r/20200625154405.60448-1-alim.akhtar@samsung.com
Fixes: 55f4b1f7 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().

Link: https://lore.kernel.org/r/20200618133837.127274-1-weiyongjun1@huawei.com
Fixes: 55f4b1f7 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
Reported-by: NHulk Robot <hulkci@huawei.com>
Acked-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allow Exynos UFS driver to build as a module.  This patch fixes the
followin build issue reported by kernel build robot.

drivers/scsi/ufs/ufs-exynos.o: in function `exynos_ufs_probe':
drivers/scsi/ufs/ufs-exynos.c:1231: undefined reference to `ufshcd_pltfrm_init'
drivers/scsi/ufs/ufs-exynos.o: in function `exynos_ufs_pre_pwr_mode':
drivers/scsi/ufs/ufs-exynos.c:635: undefined reference to `ufshcd_get_pwr_dev_param'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_shutdown'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_suspend'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_resume'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_runtime_suspend'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_runtime_resume'
drivers/scsi/ufs/ufs-exynos.o:undefined reference to `ufshcd_pltfrm_runtime_idle'

Link: https://lore.kernel.org/r/20200620173232.52521-1-alim.akhtar@samsung.com
Fixes: 55f4b1f7 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There is a spelling mistake in a dev_warn message. Fix it.

Link: https://lore.kernel.org/r/20200617084911.167359-1-colin.king@canonical.comReviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Fix build warning reported by kernel test robot:

Warning:
>> drivers/scsi/ufs/ufs-mediatek.c:181:5: warning: no previous prototype
>> for 'ufs_mtk_wait_link_state' [-Wmissing-prototypes]

Link: https://lore.kernel.org/r/20200616095120.14570-1-stanley.chu@mediatek.comReported-by: Nkernel test robot <lkp@intel.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The UFS load calculation is based on "total_time" and "busy_time" in a
devfreq window.  However, the source of time is different for both
parameters: "busy_time" is assigned from "jiffies" thus has different
accuracy from "total_time" which is assigned from ktime_get().

In addition, the time of window boundary is not exactly the same as the
starting busy time in this window if UFS is actually busy in the beginning
of the window. A similar accuracy error may also happen for the end of busy
time in current window.

To guarantee the precision of load calculation, we need to

1. Align time accuracy of both devfreq_dev_status.total_time and
   devfreq_dev_status.busy_time. For example, use "ktime_get()" directly.

2. Align the following timelines:
   - The beginning time of devfreq windows
   - The beginning of busy time in a new window
   - The end of busy time in the current window

Link: https://lore.kernel.org/r/20200611101043.6379-1-stanley.chu@mediatek.com
Fixes: a3cd5ec5 ("scsi: ufs: add load based scaling of UFS gear")
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use the ftrace infrastructure to conditionally trace UFS UIC command
events.

New trace event "ufshcd_uic_command" is created, which samples the
following UFS UIC command data:

 - Device name
 - Optional identification string
 - UIC command opcode
 - UIC command argument1
 - UIC command argument2
 - UIC command argement3

Usage:
	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
	cat /sys/kernel/debug/tracing/trace_pipe

Link: https://lore.kernel.org/r/20200615072235.23042-3-stanley.chu@mediatek.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove unused fields "cmd_active" and "result" in struct ufs_command.

Link: https://lore.kernel.org/r/20200615072235.23042-2-stanley.chu@mediatek.comReviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Clean up the following items:

 - Sort vendor names in alphabetical order

 - Squash quirks as compact as possible in device table to enhance
   performance of the lookup

 - Sort device quirks in alphabetical order

Link: https://lore.kernel.org/r/20200612012625.6615-3-stanley.chu@mediatek.comReviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It is confirmed that Micron device needs DELAY_BEFORE_LPM quirk to have a
delay before VCC is powered off. Sdd Micron vendor ID and this quirk for
Micron devices.

Link: https://lore.kernel.org/r/20200612012625.6615-2-stanley.chu@mediatek.comReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add SPDX GPL-2.0 to UFS driver files that specified the GPL version 2
license, remove the full boilerplate text.

Link: https://lore.kernel.org/r/20200605200520.20831-2-huobean@gmail.comReviewed-by: NTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For UFS 3.1, the normal unit descriptor is 10 bytes larger than the RPMB
unit. However, both descriptors share the same desc_idn, to cover both unit
descriptors with one length, we choose the normal unit descriptor length by
desc_index.

Link: https://lore.kernel.org/r/20200603091959.27618-6-huobean@gmail.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

At UFS initialization stage, to get the length of the descriptor,
ufshcd_read_desc_length() was being called 6 times. Instead, we will
capture the descriptor size the first time we'll read it.

Delete unnecessary redundant code, remove ufshcd_read_desc_length(),
ufshcd_init_desc_sizes(), and boost UFS initialization.

Link: https://lore.kernel.org/r/20200603091959.27618-5-huobean@gmail.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBart van Assche <bvanassche@acm.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If param_offset is not 0, the memcpy length shouldn't be the true
descriptor length.

Link: https://lore.kernel.org/r/20200603091959.27618-4-huobean@gmail.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Delete ufshcd_read_desc(). Instead, let caller directly call
ufshcd_read_desc_param().

Link: https://lore.kernel.org/r/20200603091959.27618-3-huobean@gmail.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBart van Assche <bvanassche@acm.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For the UFS device, the maximum descriptor size is 255, max_t called on
ufs_get_device_desc() is useless.

Link: https://lore.kernel.org/r/20200603091959.27618-2-huobean@gmail.comReviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Acked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBart van Assche <bvanassche@acm.org>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allow unbound MPHY module since not every MediaTek UFS platform needs
specific MPHY control.

Link: https://lore.kernel.org/r/20200601104646.15436-6-stanley.chu@mediatek.comReviewed-by: NPeter Wang <peter.wang@mediatek.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

MediaTek UFS clocks are separated to two parts and controlled by different
modules: ufs-mediatek and phy-ufs-mediatek.

If both Auto-Hibern8 and clk-gating feature are enabled, mphy power control
is not balanced thus unbalanced control also happens to the clocks probed
by phy-ufs-mediatek module.

Fix this issue by:

 - Promise usage of phy_power_on/off balanced

 - Remove phy_power_on/off control in suspend/resume vops since both can be
   handled in setup_clock vops only

Link: https://lore.kernel.org/r/20200601104646.15436-5-stanley.chu@mediatek.comReviewed-by: NPeter Wang <peter.wang@mediatek.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allow device power supply to enter low-power mode.

Link: https://lore.kernel.org/r/20200601104646.15436-4-stanley.chu@mediatek.comReviewed-by: NPengshun Zhao <pengshun.zhao@mediatek.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There is a chance that link enters hibern8 via auto-hibern8 scheme during
the clock-gating flow. Clocks shall not be gated if link is still active
otherwise host or device may hang.

Fix this by returning error code to the caller __ufshcd_setup_clocks() to
skip gating clocks there if link is not confirmed in hibern8 state yet.

Also allow some waiting time for the hibern8 state transition.

Link: https://lore.kernel.org/r/20200601104646.15436-3-stanley.chu@mediatek.comReviewed-by: NAndy Teng <andy.teng@mediatek.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently ref-clk control timeout is implemented by jiffies. However
jiffies is not accurate enough thus "false timeout" may happen.

Use more accurate delay mechanism instead, i.e. ktime.

Link: https://lore.kernel.org/r/20200601104646.15436-2-stanley.chu@mediatek.comReviewed-by: NAndy Teng <andy.teng@mediatek.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces Exynos UFS host controller driver which mainly
handles vendor-specific operations including link startup, power mode
change and hibernation/unhibernation.

[robot: drivers/scsi/ufs/ufs-exynos.c:931:8-10:
 WARNING: possible condition with no effect (if == else)
]

Link: https://lore.kernel.org/r/20200528011658.71590-10-alim.akhtar@samsung.comReported-by: Nkbuild test robot <lkp@intel.com>
Reported-by: NJulia Lawall <julia.lawall@lip6.fr>
Tested-by: NPaweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Reviewed-by: NKiwoong Kim <kwmad.kim@samsung.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some controller like Exynos determines if FATAL ERROR (0x7) in OCS field in
UTRD occurs for values other than GOOD (0x0) in STATUS field in response
upiu as well as errors that a host controller can't cover.  This patch is
to prevent from reporting command results in those cases.

Link: https://lore.kernel.org/r/20200528011658.71590-6-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some UFS host controllers like Exynos uses granularities of PRDT length and
offset as bytes, whereas others use actual segment count.

Link: https://lore.kernel.org/r/20200528011658.71590-5-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some host controllers don't support host controller enable via HCE.

Link: https://lore.kernel.org/r/20200528011658.71590-4-alim.akhtar@samsung.comReviewed-by: NCan Guo <cang@codeaurora.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some host controllers support interrupt aggregation but don't allow
resetting counter and timer in software.

Link: https://lore.kernel.org/r/20200528011658.71590-3-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

With the correct behavior, setting the bit to '0' indicates clear and '1'
indicates no change. If host controller handles this the other way around,
UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR can be used.

Link: https://lore.kernel.org/r/20200528011658.71590-2-alim.akhtar@samsung.comReviewed-by: NCan Guo <cang@codeaurora.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Since commit 84af7a61 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

In ufshcd_probe_hba(), all BKOP SW tracking variables can be reset together
in ufshcd_force_reset_auto_bkops(), thus urgent_bkop_lvl initialization in
the beginning of ufshcd_probe_hba() can be merged into
ufshcd_force_reset_auto_bkops().

Link: https://lore.kernel.org/r/20200530141200.4616-1-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Urgent bkops level is used to compare against actual bkops status read from
UFS device. Urgent bkops level is set during initialization and might be
updated in exception event handler during runtime. But it should not be
updated to the actual bkops status every time when auto bkops is toggled.
Otherwise, if urgent bkops level is updated to 0, auto bkops shall always
be kept enabled.

Link: https://lore.kernel.org/r/1590632686-17866-1-git-send-email-cang@codeaurora.org
Fixes: 24366c2a ("scsi: ufs: Recheck bkops level if bkops is disabled")
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Fix unwinding of pm_runtime changes when bailing out of driver probe due to
a failure and also on removal of driver.

Link: https://lore.kernel.org/r/20200526100340.15032-1-vigneshr@ti.com
Fixes: 6979e56c ("scsi: ufs: Add driver for TI wrapper for Cadence UFS IP")
Reported-by: NDinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: NVignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently UFS host driver promises VCC supply if UFS device needs to do
WriteBooster flush during runtime suspend.

However the UFS specification mentions:

"While the flushing operation is in progress, the device is in Active power
mode."

Therefore UFS host driver needs to promise more: Keep UFS device as "Active
power mode", otherwise UFS device shall not do any flush if device enters
Sleep or PowerDown power mode.  Similarly, the same promises shall be
applied if device needs urgent BKOP during runtime suspend.

Fix this by not changing device power mode if WriteBooster flush or urgent
BKOP is required in ufshcd_suspend().

Now, if device finishes its job but is not resumed for a very long time,
system will have unnecessary power drain because VCC is still supplied. A
method to re-check the threshold of keeping VCC supply is required to fix
the power drain. However, the threshold re-check needs to re-activate the
link first because the decision depends on the latest device status.

Also introduce a delayed work to force runtime resume after a certain delay
during runtime suspend. This makes threshold re-check happen natually in
the entry of the next runtime-suspend. The device can continue its
WriteBooster flush or urgent BKOP jobs soon after resumed if device has no
upcoming requests and link enters hibern8 state either by Auto-Hibern8 or
hibern8 during clk-gating scheme. This solution not only prevents power
drain but also makes as much use of time as possible for device's
background jobs.

Link: https://lore.kernel.org/r/20200522083212.4008-5-stanley.chu@mediatek.comReviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For WriteBooster feature related attributes, the index used by query shall
be LUN ID if LU Dedicated buffer mode is enabled.

Link: https://lore.kernel.org/r/20200522083212.4008-4-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

According to the UFS specification, WriteBooster is officially supported by
UFS 2.2.

Since UFS 2.2 specification has been finalized in JEDEC and such devices
have also showed up in the market, modify the checking rule for
ufshcd_wb_probe() to allow these devices to enable WriteBooster.

Link: https://lore.kernel.org/r/20200522083212.4008-3-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The whole UFS host instance has been zero-initialized by scsi_host_alloc(),
thus UFS driver does not need to clear "dev_info" member specifically in
ufshcd_device_params_init().

Simply remove the unnecessary code.

Link: https://lore.kernel.org/r/20200522083212.4008-2-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

ufs_qcom_dump_dbg_regs() uses usleep_range, a sleeping function, but can be
called from atomic context in the following flow:

ufshcd_intr -> ufshcd_sl_intr -> ufshcd_check_errors ->
ufshcd_print_host_regs -> ufshcd_vops_dbg_register_dump ->
ufs_qcom_dump_dbg_regs

This causes a boot crash on the Lenovo Miix 630 when the interrupt is
handled on the idle thread.

Fix the issue by switching to udelay().

Link: https://lore.kernel.org/r/20200525204125.46171-1-jeffrey.l.hugo@gmail.com
Fixes: 9c46b867 ("scsi: ufs-qcom: dump additional testbus registers")
Reviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NJeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The ufshcd_wait_for_register() function either sleeps or spins until the
specified register has reached the desired value. Busy-waiting is not only
considered a bad practice but also has a bad impact on energy
consumption. Always sleep instead of spinning by making sure that all
ufshcd_wait_for_register() calls happen from a context where it is allowed
to sleep. The only function call that has to be moved is the
ufshcd_hba_stop() call in ufshcd_host_reset_and_restore().

Link: https://lore.kernel.org/r/20200507222750.19113-1-bvanassche@acm.org
Cc: Can Guo <cang@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Tested-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>