<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/clocksource/Kconfig, branch v5.0-rc3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>clocksource/drivers/rda: Add clock driver for RDA8810PL SoC</title>
<updated>2018-12-18T21:22:23+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@linaro.org</email>
</author>
<published>2018-12-10T17:35:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7f83a1327962b9b3712866db8cbafbdee239cce4'/>
<id>7f83a1327962b9b3712866db8cbafbdee239cce4</id>
<content type='text'>
Add clock driver for RDA Micro RDA8810PL SoC supporting OSTIMER
and HWTIMER.

RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER
(64 bit). Each timer provides optional interrupt support. In this
driver, OSTIMER is used for clockevents and HWTIMER is used for
clocksource.

Signed-off-by: Andreas Färber &lt;afaerber@suse.de&gt;
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add clock driver for RDA Micro RDA8810PL SoC supporting OSTIMER
and HWTIMER.

RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER
(64 bit). Each timer provides optional interrupt support. In this
driver, OSTIMER is used for clockevents and HWTIMER is used for
clocksource.

Signed-off-by: Andreas Färber &lt;afaerber@suse.de&gt;
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/riscv_timer: Provide the sched_clock</title>
<updated>2018-12-18T21:22:23+00:00</updated>
<author>
<name>Anup Patel</name>
<email>anup@brainfault.org</email>
</author>
<published>2018-12-04T10:29:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=92e0d143fdef1faa7560c93fb0d6cd6c61da88ee'/>
<id>92e0d143fdef1faa7560c93fb0d6cd6c61da88ee</id>
<content type='text'>
Currently, we don't have a sched_clock registered for RISC-V systems.
This means Linux time keeping will use jiffies (running at HZ) as the
default sched_clock.

To avoid this, we explicity provide sched_clock using RISC-V rdtime
instruction (similar to riscv_timer clocksource).

Signed-off-by: Anup Patel &lt;anup@brainfault.org&gt;
Reviewed-by: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, we don't have a sched_clock registered for RISC-V systems.
This means Linux time keeping will use jiffies (running at HZ) as the
default sched_clock.

To avoid this, we explicity provide sched_clock using RISC-V rdtime
instruction (similar to riscv_timer clocksource).

Signed-off-by: Anup Patel &lt;anup@brainfault.org&gt;
Reviewed-by: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/arc_timer: Utilize generic sched_clock</title>
<updated>2018-12-18T21:22:23+00:00</updated>
<author>
<name>Alexey Brodkin</name>
<email>alexey.brodkin@synopsys.com</email>
</author>
<published>2018-11-19T11:29:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf287607c80f24387fedb431a346dc67f25be12c'/>
<id>bf287607c80f24387fedb431a346dc67f25be12c</id>
<content type='text'>
It turned out we used to use default implementation of sched_clock()
from kernel/sched/clock.c which was as precise as 1/HZ, i.e.
by default we had 10 msec granularity of time measurement.

Now given ARC built-in timers are clocked with the same frequency as
CPU cores we may get much higher precision of time tracking.

Thus we switch to generic sched_clock which really reads ARC hardware
counters.

This is especially helpful for measuring short events.
That's what we used to have:
------------------------------&gt;8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello &gt; /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

         10.000000      task-clock (msec)         #    2.832 CPUs utilized
                 1      context-switches          #    0.100 K/sec
                 1      cpu-migrations            #    0.100 K/sec
                63      page-faults               #    0.006 M/sec
           3049480      cycles                    #    0.305 GHz
           1091259      instructions              #    0.36  insn per cycle
            256828      branches                  #   25.683 M/sec
             27026      branch-misses             #   10.52% of all branches

       0.003530687 seconds time elapsed

       0.000000000 seconds user
       0.010000000 seconds sys
------------------------------&gt;8------------------------

And now we'll see:
------------------------------&gt;8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello &gt; /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

          3.004322      task-clock (msec)         #    0.865 CPUs utilized
                 1      context-switches          #    0.333 K/sec
                 1      cpu-migrations            #    0.333 K/sec
                63      page-faults               #    0.021 M/sec
           2986734      cycles                    #    0.994 GHz
           1087466      instructions              #    0.36  insn per cycle
            255209      branches                  #   84.947 M/sec
             26002      branch-misses             #   10.19% of all branches

       0.003474829 seconds time elapsed

       0.003519000 seconds user
       0.000000000 seconds sys
------------------------------&gt;8------------------------

Note how much more meaningful is the second output - time spent for
execution pretty much matches number of cycles spent (we're runnign
@ 1GHz here).

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It turned out we used to use default implementation of sched_clock()
from kernel/sched/clock.c which was as precise as 1/HZ, i.e.
by default we had 10 msec granularity of time measurement.

Now given ARC built-in timers are clocked with the same frequency as
CPU cores we may get much higher precision of time tracking.

Thus we switch to generic sched_clock which really reads ARC hardware
counters.

This is especially helpful for measuring short events.
That's what we used to have:
------------------------------&gt;8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello &gt; /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

         10.000000      task-clock (msec)         #    2.832 CPUs utilized
                 1      context-switches          #    0.100 K/sec
                 1      cpu-migrations            #    0.100 K/sec
                63      page-faults               #    0.006 M/sec
           3049480      cycles                    #    0.305 GHz
           1091259      instructions              #    0.36  insn per cycle
            256828      branches                  #   25.683 M/sec
             27026      branch-misses             #   10.52% of all branches

       0.003530687 seconds time elapsed

       0.000000000 seconds user
       0.010000000 seconds sys
------------------------------&gt;8------------------------

And now we'll see:
------------------------------&gt;8------------------------
$ perf stat /bin/sh -c /root/lmbench-master/bin/arc/hello &gt; /dev/null

 Performance counter stats for '/bin/sh -c /root/lmbench-master/bin/arc/hello':

          3.004322      task-clock (msec)         #    0.865 CPUs utilized
                 1      context-switches          #    0.333 K/sec
                 1      cpu-migrations            #    0.333 K/sec
                63      page-faults               #    0.021 M/sec
           2986734      cycles                    #    0.994 GHz
           1087466      instructions              #    0.36  insn per cycle
            255209      branches                  #   84.947 M/sec
             26002      branch-misses             #   10.19% of all branches

       0.003474829 seconds time elapsed

       0.003519000 seconds user
       0.000000000 seconds sys
------------------------------&gt;8------------------------

Note how much more meaningful is the second output - time spent for
execution pretty much matches number of cycles spent (we're runnign
@ 1GHz here).

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/imx-gpt: Add support for ARM64</title>
<updated>2018-12-18T21:22:23+00:00</updated>
<author>
<name>Anson Huang</name>
<email>anson.huang@nxp.com</email>
</author>
<published>2018-11-05T01:10:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=df181e38281602bb404c5c8158a87317274dc653'/>
<id>df181e38281602bb404c5c8158a87317274dc653</id>
<content type='text'>
This patch allows building and compile-testing the i.MX GPT driver
also for ARM64. The delay_timer is only supported on ARMv7.

Signed-off-by: Anson Huang &lt;Anson.Huang@nxp.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch allows building and compile-testing the i.MX GPT driver
also for ARM64. The delay_timer is only supported on ARMv7.

Signed-off-by: Anson Huang &lt;Anson.Huang@nxp.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/ux500: Drop Ux500 custom SCHED_CLOCK</title>
<updated>2018-12-18T21:22:23+00:00</updated>
<author>
<name>Linus Walleij</name>
<email>linus.walleij@linaro.org</email>
</author>
<published>2018-11-15T13:32:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=85b6fcadcf6626ad520376eacfb2b77090e782ab'/>
<id>85b6fcadcf6626ad520376eacfb2b77090e782ab</id>
<content type='text'>
The two drivers used for Ux500 sched_clock use two Kconfig
symbols to select which of the two gets used as sched_clock.

This isn't right: the workaround is trying to make sure that
the NONSTOP timer is used for sched_clock in order to keep
that clock ticking consistently over a suspend/resume
cycle. (Otherwise sched_clock simply stops during suspend
and continues after resume).

This will notably affect any timetstamped debug prints,
so that they show the absolute number of seconds since the
system was booted and does not loose wall-clock time during
suspend and resume as if time stood still.

The real way to fix this problem is to make sched_clock
take advantage of any NONSTOP clock source on the system
and adjust accordingly, not to try to work around this by
using a different sched_clock depending on what system
we are compiling for. This can solve the problem for
everyone instead of providing a local solution.

Cc: Baolin Wang &lt;baolin.wang@linaro.org&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The two drivers used for Ux500 sched_clock use two Kconfig
symbols to select which of the two gets used as sched_clock.

This isn't right: the workaround is trying to make sure that
the NONSTOP timer is used for sched_clock in order to keep
that clock ticking consistently over a suspend/resume
cycle. (Otherwise sched_clock simply stops during suspend
and continues after resume).

This will notably affect any timetstamped debug prints,
so that they show the absolute number of seconds since the
system was booted and does not loose wall-clock time during
suspend and resume as if time stood still.

The real way to fix this problem is to make sched_clock
take advantage of any NONSTOP clock source on the system
and adjust accordingly, not to try to work around this by
using a different sched_clock depending on what system
we are compiling for. This can solve the problem for
everyone instead of providing a local solution.

Cc: Baolin Wang &lt;baolin.wang@linaro.org&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/c-sky: Add gx6605s SOC system timer</title>
<updated>2018-11-02T18:41:12+00:00</updated>
<author>
<name>Guo Ren</name>
<email>ren_guo@c-sky.com</email>
</author>
<published>2018-11-02T16:51:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=33745c3cc588d9d5e18d6fd88709002158dddd5e'/>
<id>33745c3cc588d9d5e18d6fd88709002158dddd5e</id>
<content type='text'>
The driver is for gx6605s SOC system timer and there are two
same timers in gx6605s. We use one for clkevt and another one for
clksrc.

The timer is mmio map to access, so we need give mmio address in dts.

The counter at 0x0  offset is clock event.
The counter at 0x40 offset is clock source.

Signed-off-by: Guo Ren &lt;ren_guo@c-sky.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The driver is for gx6605s SOC system timer and there are two
same timers in gx6605s. We use one for clkevt and another one for
clksrc.

The timer is mmio map to access, so we need give mmio address in dts.

The counter at 0x0  offset is clock event.
The counter at 0x40 offset is clock source.

Signed-off-by: Guo Ren &lt;ren_guo@c-sky.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/c-sky: Add C-SKY SMP timer</title>
<updated>2018-11-02T18:39:54+00:00</updated>
<author>
<name>Guo Ren</name>
<email>ren_guo@c-sky.com</email>
</author>
<published>2018-11-02T16:51:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a7ad38b0dd3c1ba8d6e5a55241e875e9db8331ab'/>
<id>a7ad38b0dd3c1ba8d6e5a55241e875e9db8331ab</id>
<content type='text'>
The driver is for C-SKY SMP timer. It only supports oneshot event
and 32bit overflow for clocksource. Per cpu core has one timer and
all timers share one clock-counter-input from the same clocksource.

This use mfcr&amp;mtcr instructions to access the regs.

Signed-off-by: Guo Ren &lt;ren_guo@c-sky.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The driver is for C-SKY SMP timer. It only supports oneshot event
and 32bit overflow for clocksource. Per cpu core has one timer and
all timers share one clock-counter-input from the same clocksource.

This use mfcr&amp;mtcr instructions to access the regs.

Signed-off-by: Guo Ren &lt;ren_guo@c-sky.com&gt;
Cc: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource: new RISC-V SBI timer driver</title>
<updated>2018-08-13T15:31:31+00:00</updated>
<author>
<name>Palmer Dabbelt</name>
<email>palmer@dabbelt.com</email>
</author>
<published>2018-08-04T08:23:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=62b0194368147def8c5a77ce604a125d620fc582'/>
<id>62b0194368147def8c5a77ce604a125d620fc582</id>
<content type='text'>
The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra &lt;atish.patra@wdc.com&gt;.

Signed-off-by: Dmitriy Cherkasov &lt;dmitriy@oss-tech.org&gt;
Signed-off-by: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Atish Patra &lt;atish.patra@wdc.com&gt;
Signed-off-by: Palmer Dabbelt &lt;palmer@sifive.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra &lt;atish.patra@wdc.com&gt;.

Signed-off-by: Dmitriy Cherkasov &lt;dmitriy@oss-tech.org&gt;
Signed-off-by: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Atish Patra &lt;atish.patra@wdc.com&gt;
Signed-off-by: Palmer Dabbelt &lt;palmer@sifive.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>clocksource/drivers/sprd: Fix Kconfig dependency</title>
<updated>2018-05-18T20:53:08+00:00</updated>
<author>
<name>Chunyan Zhang</name>
<email>chunyan.zhang@spreadtrum.com</email>
</author>
<published>2018-05-07T09:04:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8a1ece26d370e38817da5232195896b727dba3cd'/>
<id>8a1ece26d370e38817da5232195896b727dba3cd</id>
<content type='text'>
SPRD arch doesn't select SPRD_TIMER, so this config would not
appear even if ARCH_SPRD is set but COMPILE_TEST not.

Fix the dependency of this config with SPRD arch, and set a
default value for it, also leave other choices for EXPERT.

Signed-off-by: Chunyan Zhang &lt;chunyan.zhang@spreadtrum.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
SPRD arch doesn't select SPRD_TIMER, so this config would not
appear even if ARCH_SPRD is set but COMPILE_TEST not.

Fix the dependency of this config with SPRD arch, and set a
default value for it, also leave other choices for EXPERT.

Signed-off-by: Chunyan Zhang &lt;chunyan.zhang@spreadtrum.com&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2018-04-16T19:44:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-04-16T19:44:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d95c8844399885cd511c6f6395621cc1a9fe2e68'/>
<id>d95c8844399885cd511c6f6395621cc1a9fe2e68</id>
<content type='text'>
Pull missed timer updates from Thomas Gleixner:
 "This is a branch which got forgotten during the merge window, but it
  contains only fixes and hardware enablement. No fundamental changes.

   - Various fixes for the imx-tpm clocksource driver

   - A new timer driver for the NCPM7xx SoC family"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/imx-tpm: Add different counter width support
  clocksource/drivers/imx-tpm: Correct some registers operation flow
  clocksource/drivers/imx-tpm: Fix typo of clock name
  dt-bindings: timer: tpm: fix typo of clock name
  clocksource/drivers/npcm: Add NPCM7xx timer driver
  dt-binding: timer: document NPCM7xx timer DT bindings
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull missed timer updates from Thomas Gleixner:
 "This is a branch which got forgotten during the merge window, but it
  contains only fixes and hardware enablement. No fundamental changes.

   - Various fixes for the imx-tpm clocksource driver

   - A new timer driver for the NCPM7xx SoC family"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/imx-tpm: Add different counter width support
  clocksource/drivers/imx-tpm: Correct some registers operation flow
  clocksource/drivers/imx-tpm: Fix typo of clock name
  dt-bindings: timer: tpm: fix typo of clock name
  clocksource/drivers/npcm: Add NPCM7xx timer driver
  dt-binding: timer: document NPCM7xx timer DT bindings
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