Accordingly to Cadence documentation, PHY write procedure is:
1. Software sets the PHY Register Address (HRS04[5:0]) and the
PHY Write Data (HRS04[15:8]) fields.
2. Software sets the PHY Write Transaction Request (HRS04[24]) field to 1.
3. Software waits as the PHY Write Transaction Acknowledge (HRS04[26])
field is equal to 0.
4. Hardware performs the write transaction to PHY register where
HRS04[15:8] is a data written to register under HRS04[5:0] address.
5. Hardware sets the PHY Transaction Acknowledge (HRS04[26]) to 1 when
transaction is completed.
6. Software clears the PHY Write Transaction Request (HRS04[24]) to 1
after noticing that the PHY Write Transaction Acknowledge (HRS04[26])
field is equal to 1.
7. Software waits for the PHY Acknowledge Register (HRS04[26]) field is
equal to 0.
Add missing steps 3 and 7. Lack of these steps causes
integrity errors detested by hardware.
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Link: https://lore.kernel.org/r/20200525074053.7309-1-vladimir.kondratiev@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Fix ordering of SDIO IDs to conform to the comment above, which says vendor
first, device next.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-12-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
All macro names for SDIO device IDs are prefixed by vendor name to which
device ID belongs. So for consistency add Broadcom string vendor prefix to
all Cypress macro names as they belong to SDIO Broadcom vendor ID.
Change also Cypress 43012 value from decimal do hexadecimal notation to be
consistent with all other values.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-11-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Also replace generic MANUFACTURER macros by proper SDIO IDs macros.
Checks for device IDs are slightly modified to use SDIO device IDs.
This allows removal of all custom MANUFACTURER macros from ath10k.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-9-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Also replace generic MANUFACTURER macros by proper SDIO IDs macros.
Check for "AR6003 or later" is slightly modified to use SDIO device IDs.
This allows removal of all custom MANUFACTURER macros from ath6kl.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200522144412.19712-8-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Add _WLAN suffix to macro names for consistency with other Marvell macros.
These IDs represents wlan function of combo bt/wlan cards. Other functions
of these cards have different IDs.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200522144412.19712-4-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Marvell SDIO device ID 0x9134 is used in SDIO Common CIS (Card Information
Structure) and not in SDIO wlan function (with ID 1). SDIO Common CIS is
accessed by function ID 0.
So change this misleading macro name to SDIO_DEVICE_ID_MARVELL_8887_F0 as
it does not refer to wlan function. It refers to function 0.
Wlan module on this SDIO card is available at function ID 1 and is
identified by different SDIO device ID 0x9135. Kernel quirks for SDIO
devices are matched against device ID from SDIO Common CIS. Therefore
device ID used in quirk is correct, just has misleading name.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200522144412.19712-2-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The eSDHC HS400 timing requires many specific registers setting,
unlike other speed modes which need to set only host controller 2
register. When driver needs to downgrade HS400 mode to other speed
mode, the controller have to exit HS400 timing properly first.
This patch is to support the procedure of HS400 exiting at the
beginning of esdhc_set_uhs_signaling.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200522031256.856-1-yangbo.lu@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Implement dump_vendor_registers host operation to print the
vendor specific registers in addition to standard SDHC
register during error conditions.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-9-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Introduce new sdhci ops to dump vendor specific registers in the
sdhci_dumpregs during error.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-8-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Certain platforms require different settings in the
SDCC_HC_REG_DLL_CONFIG register. This setting can change from platform
to platform. So the driver should check whether a particular platform
require a different setting by reading the DT file and use it.
Also use msm_cm_dll_set_freq only when DLL not supplied.
Signed-off-by: Bao D. Nguyen <nguyenb@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-7-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Certain platforms require different settings in the
SDCC_HC_REG_DDR_CONFIG register. This setting can change from platform
to platform. So the driver should check whether a particular platform
require a different setting by reading the device tree file and use it.
Signed-off-by: Bao D. Nguyen <nguyenb@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-6-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Update dll_config_3 as per the host clock frequency as specified in the
DLL Hardware Reference Guide.
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-5-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
With SDCC v5.1.0, additional setting needed for enabling DLL output.
The dll-user-control register need to be configured during dll
initialization for getting proper dll output.
Without this configuration, we don't get the DLL lock status properly.
Also update the DLL register settings according to the SDCC Hardware
Programming Guide.
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590139950-7288-4-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Add information regarding DLL register properties for getting board
specific configurations. These DLL register settings may vary from
board to board.
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
Link: https://lore.kernel.org/r/1590139950-7288-3-git-send-email-sartgarg@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
When auto calibration timeouts, calibration is disabled and fail-safe
drive strength values are programmed based on the signal voltage.
Different fail-safe drive strength values based on voltage are
applicable only for SoCs supporting 3V3 and 1V8 pad controls.
So, this patch avoids reading these properties from the device tree
for SoCs not using pad controls and the warning of missing properties
will not show up on these SoC platforms.
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1590005337-1087-1-git-send-email-skomatineni@nvidia.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If the tmio device is attached to a genpd (PM domain), that genpd may have
->start|stop() callback assigned to it. To make sure the device is
accessible during ->probe(), genpd's ->start() callback must be invoked,
which is currently managed by tmio_mmc_host_probe(). However, it's likely
that may be too late for some cases, as registers may be read and written
way before that point.
To fix the behaviour, let's move the call to dev_pm_domain_start() from
tmio_mmc_host_probe() into those clients that needs it. From discussions at
linux-mmc mailing list, it turned out that it should be sufficient to do
this for the SDHI renesas variants, hence the call is move to
renesas_sdhi_probe().
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20200519152445.6922-1-ulf.hansson@linaro.org
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Before calling tmio_mmc_host_probe(), the caller is required to enable
clocks for its device, as to make it accessible when reading/writing
registers during probe.
Therefore, the responsibility to disable these clocks, in the error path of
->probe() and during ->remove(), is better managed outside
tmio_mmc_host_remove(). As a matter of fact, callers of
tmio_mmc_host_remove() already expects this to be the behaviour.
However, there's a problem with tmio_mmc_host_remove() when the Kconfig
option, CONFIG_PM, is set. More precisely, tmio_mmc_host_remove() may then
disable the clock via runtime PM, which leads to clock enable/disable
imbalance problems, when the caller of tmio_mmc_host_remove() also tries to
disable the same clocks.
To solve the problem, let's make sure tmio_mmc_host_remove() leaves the
device with clocks enabled, but also make sure to disable the IRQs, as we
normally do at ->runtime_suspend().
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200519152434.6867-1-ulf.hansson@linaro.org
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
This driver has been developed as a separate module starting
from the similar sdhci-esdhc-imx.c.
Reasons for a separate sdchi-esdhc-mcf driver:
- m68K architecture does not support devicetrees, so modifying
sdhci-of-esdhc.c that is devicetree-related adding platform data
seems not appropriate,
- clock-related part, has to be implemented specifically for
mcf5441x family (see esdhc_mcf_pltfm_set_clock()),
- this is a big endian cpu accessing a big endian controller,
but about sdma, this controller does not support hw swap, which
needs to be handled with specific code,
- some other minor differences but mainly to avoid risks on
tweaking inside largely used imx driver. Adding just a small
size ColdFire-specific driver, with benefits in a further less
risky maintenance.
Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200518191742.1251440-3-angelo.dureghello@timesys.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Some controller as the ColdFire eshdc may require an endianness
byte swap, because DMA read endianness is not configurable.
Facilitate using the bounce buffer for this by adding
->copy_to_bounce_buffer().
Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200518191742.1251440-2-angelo.dureghello@timesys.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Kbuild test robot reports the following warning in lines 56 and 87 of
drivers/mmc/host/meson-mx-sdhc-clkc.c:
Using plain integer as NULL pointer
Drop the integer value from the struct initialization to fix that
warning. This will still ensure that the compiler will zero out the
struct so it's in a well-defined state.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20200517222907.1277787-2-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
For Meson8 and Meson8b SoCs the vendor driver follows the following
pattern:
- for eMMC and SD cards in .set_pdma it sets:
pdma->rxfifo_manual_flush = 1;
- for SDIO cards in .set_pdma it sets:
pdma->rxfifo_manual_flush = 0;
- before syncing the DMA read buffer is sets:
pdma->rxfifo_manual_flush |= 0x02;
Set the second bit of MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH without
clearing the first bit before syncing the DMA read buffer. This fixes a
problem where Meson8 and Meson8b SoCs would read random garbage from SD
cards. It is not clear why it worked for eMMC cards. This manifested in
the following errors when plugging in an SD card:
unrecognised SCR structure version <random number>
Cc: Thomas Graichen <thomas.graichen@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20200517222907.1277787-1-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
For an x86_64 allmodconfig build Stephen reports that building
meson-mx-sdhc-clkc.o warns that MODULE_LICENSE is missing and when
linking meson_mx_sdhc_register_clkc cannot be found.
Compile the MMC controller driver together with the build-in clock
controller driver into one module rather than using two separate
modules to fix these issues.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20200518060811.1499962-1-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
We need a different set_uhs_signaling implementation for
MMC_TIMING_MMC_HS and MMC_TIMING_MMC_HS400.
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200513182602.3636a551@xhacker.debian
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The SDHC MMC host controller on Amlogic SoCs provides an eMMC and MMC
card interface with 1/4/8-bit bus width.
It supports eMMC spec 4.4x/4.5x including HS200 (up to 100MHz clock).
The public S805 datasheet [0] contains a short documentation about the
registers. Unfortunately it does not describe how to use the registers
to make the hardware work. Thus this driver is based on reading (and
understanding) the Amlogic 3.10 GPL kernel code.
Some hardware details are not easy to see. Jianxin Pan was kind enough
to answer my questions:
The hardware has built-in busy timeout support. The maximum timeout is
30 seconds. This is only documented in Amlogic's internal
documentation.
The controller only works with very specific clock configurations. The
details are not part of the public datasheet. In my own words the
supported configurations are:
- 399.812kHz: clkin = 850MHz div = 2126 sd_rx_phase = 63
- 1MHz: clkin = 850MHz div = 850 sd_rx_phase = 55
- 5.986MHz: clkin = 850MHz div = 142 sd_rx_phase = 24
- 25MHz: clkin = 850MHz div = 34 sd_rx_phase = 15
- 47.222MHz: clkin = 850MHz div = 18 sd_rx_phase = 11/15 (SDR50/HS)
- 53.125MHz: clkin = 850MHz div = 16 sd_rx_phase = (tuning)
- 70.833MHz: clkin = 850MHz div = 12 sd_rx_phase = (tuning)
- 85MHz: clkin = 850MHz div = 10 sd_rx_phase = (tuning)
- 94.44MHz: clkin = 850MHz div = 9 sd_rx_phase = (tuning)
- 106.25MHz: clkin = 850MHz div = 8 sd_rx_phase = (tuning)
- 127.5MHz: clkin = 1275MHz div = 10 sd_rx_phase = (tuning)
- 141.667MHz: clkin = 850MHz div = 6 sd_rx_phase = (tuning)
- 159.375MHz: clkin = 1275MHz div = 8 sd_rx_phase = (tuning)
- 212.5MHz: clkin = 1275MHz div = 6 sd_rx_phase = (tuning)
- (sd_tx_phase is always 1, 94.44MHz is not listed in the datasheet
but this is what the 3.10 BSP kernel on Odroid-C1 actually uses)
NOTE: CMD23 support is disabled for now because it results in command
timeouts and thus decreases read performance.
Tested-by: Wei Wang <lnykww@gmail.com>
Tested-by: Xin Yin <yinxin_1989@aliyun.com>
Reviewed-by: Xin Yin <yinxin_1989@aliyun.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200512204147.504087-3-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This documents the devicetree bindings for the SDHC MMC host controller
found in Meson6, Meson8, Meson8b and Meson8m2 SoCs. It can use a
bus-width of 1/4/8-bit and it supports eMMC spec 4.4x/4.5x including
HS200 mode (up to 100MHz clock). It embeds an internal clock controller
which outputs four clocks (mod_clk, sd_clk, tx_clk and rx_clk) and is
fed by four external input clocks (clkin[0-3]). "pclk" is the module
register clock, it has to be enabled to access the registers.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200512204147.504087-2-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The definitions of MMC_IOC_CMD and of MMC_IOC_MULTI_CMD rely on
MMC_BLOCK_MAJOR:
#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)
#define MMC_IOC_MULTI_CMD _IOWR(MMC_BLOCK_MAJOR, 1, struct mmc_ioc_multi_cmd)
However, MMC_BLOCK_MAJOR is defined in linux/major.h and
linux/mmc/ioctl.h did not include it.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200511161902.191405-1-Jerome.Pouiller@silabs.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Use FIELD_GET and FIELD_PREP to get access to the register fields. Delete
the shift macros and use GENMASK() for the touched macros.
Note that, this has the side-effect of changing the constants to 64-bit on
64-bit platforms.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/r/20200511062828.1791484-1-yamada.masahiro@socionext.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Currently, tmio_mmc_irq() handler is registered before the host is
fully initialized by tmio_mmc_host_probe(). I did not previously notice
this problem.
The boot ROM of a new Socionext SoC unmasks interrupts (CTL_IRQ_MASK)
somehow. The handler is invoked before tmio_mmc_host_probe(), then
emits noisy call trace.
Move devm_request_irq() below tmio_mmc_host_probe().
Fixes: 3fd784f745 ("mmc: uniphier-sd: add UniPhier SD/eMMC controller driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200511062158.1790924-1-yamada.masahiro@socionext.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
GL9763E supports High Speed SDR, High Speed DDR, HS200, HS400, Enhanced
Strobe in HS400 mode, 1/4/8 bits data bus and 3.3/1.8V.
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Link: https://lore.kernel.org/r/20200508064154.13473-1-benchuanggli@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The MMC_CAP_ERASE bit is no longer used by the mmc core as erase, discard
and trim operations are now always supported. Therefore, drop the bit and
move all mmc hosts away from using it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Link: https://lore.kernel.org/r/20200508112902.23575-1-ulf.hansson@linaro.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Step by step, mmc host drivers and the mmc core have been improved in
regards to support erase/discard/trim operations. We have now reached a
point when it no longer seems reasonable to use an opt-in approach to
enable the functionality. Therefore, let's switch to make the operations
always supported.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200508112853.23525-1-ulf.hansson@linaro.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Using a fixed 1s polling timeout for all commands is a bit problematic.
For some commands it means waiting longer than needed for the polling to be
aborted, which may not a big issue, but still. For other commands, like for
an erase (CMD38) that uses a R1B response, may require longer timeouts than
1s. In these cases, we may end up treating the command as it failed, while
it just needed some more time to complete successfully.
Fix the problem by respecting the cmd->busy_timeout, which is provided by
the mmc core.
Note that, even if the sdricoh_cs driver may currently not support HW busy
detection on DAT0, some comments in the code refer to that the HW may
support it. Therefore, it seems better to be proactive in this case.
Cc: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200508095228.14230-1-ulf.hansson@linaro.org
Rather than to poll in a busy-loop, let's convert into using
read_poll_timeout() and insert a small delay between each polling attempts.
In particular, this avoids hogging the CPU.
Additionally, to convert to read_poll_timeout() we also need to switch from
using a specific number of polling attempts, into a specific timeout in us
instead. The previous 100000 attempts, is translated into a total timeout
of total 1s, as that seemed like reasonable value to pick.
Cc: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200508095218.14177-1-ulf.hansson@linaro.org
Rather than to poll in a busy-loop, let's convert into using
read_poll_timeout() and insert a small delay between each polling attempts.
In particular, this avoids hogging the CPU.
Additionally, to convert to read_poll_timeout() we also need to switch from
using a specific number of polling attempts, into a specific timeout in us
instead. The previous 100000 attempts, is translated into a total timeout
of total 1s, as that seemed like reasonable value to pick.
Cc: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200508095210.14123-1-ulf.hansson@linaro.org
Wan Ahmad Zainie
Vladimir Kondratiev
Pali Rohár
Ulf Hansson
Angelo Dureghello
Yangbo Lu
Sarthak Garg
Veerabhadrarao Badiganti
Sowjanya Komatineni
Wolfram Sang
Lad Prabhakar
Martin Blumenstingl
Haibo Chen
Jisheng Zhang
Jérôme Pouiller
Masahiro Yamada
Ben Chuang