<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/i2c, branch v4.19.30</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>i2c: omap: Use noirq system sleep pm ops to idle device for suspend</title>
<updated>2019-03-13T21:02:38+00:00</updated>
<author>
<name>Tony Lindgren</name>
<email>tony@atomide.com</email>
</author>
<published>2019-01-10T15:59:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ee84b62fba23ebdddb81ebe3f8275ad69d5f7ed7'/>
<id>ee84b62fba23ebdddb81ebe3f8275ad69d5f7ed7</id>
<content type='text'>
[ Upstream commit c6e2bd956936d925748581e4d0294f10f1d92f2c ]

We currently get the following error with pixcir_ts driver during a
suspend resume cycle:

omap_i2c 4802a000.i2c: controller timed out
pixcir_ts 1-005c: pixcir_int_enable: can't read reg 0x34 : -110
pixcir_ts 1-005c: Failed to disable interrupt generation: -110
pixcir_ts 1-005c: Failed to stop
dpm_run_callback(): pixcir_i2c_ts_resume+0x0/0x98
[pixcir_i2c_ts] returns -110
PM: Device 1-005c failed to resume: error -110

And at least am437x based devices with pixcir_ts will fail to resume
to a touchscreen that is configured as the wakeup-source in device
tree for these devices.

This is because pixcir_ts tries to reconfigure it's registers for
noirq suspend which fails. This also leaves i2c-omap in enabled state
for suspend.

Let's fix the pixcir_ts issue and make sure i2c-omap is suspended by
adding SET_NOIRQ_SYSTEM_SLEEP_PM_OPS.

Let's also get rid of some ifdefs while at it and replace them with
__maybe_unused as SET_RUNTIME_PM_OPS and SET_NOIRQ_SYSTEM_SLEEP_PM_OPS
already deal with the various PM Kconfig options.

Reported-by: Keerthy &lt;j-keerthy@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Acked-by: Vignesh R &lt;vigneshr@ti.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c6e2bd956936d925748581e4d0294f10f1d92f2c ]

We currently get the following error with pixcir_ts driver during a
suspend resume cycle:

omap_i2c 4802a000.i2c: controller timed out
pixcir_ts 1-005c: pixcir_int_enable: can't read reg 0x34 : -110
pixcir_ts 1-005c: Failed to disable interrupt generation: -110
pixcir_ts 1-005c: Failed to stop
dpm_run_callback(): pixcir_i2c_ts_resume+0x0/0x98
[pixcir_i2c_ts] returns -110
PM: Device 1-005c failed to resume: error -110

And at least am437x based devices with pixcir_ts will fail to resume
to a touchscreen that is configured as the wakeup-source in device
tree for these devices.

This is because pixcir_ts tries to reconfigure it's registers for
noirq suspend which fails. This also leaves i2c-omap in enabled state
for suspend.

Let's fix the pixcir_ts issue and make sure i2c-omap is suspended by
adding SET_NOIRQ_SYSTEM_SLEEP_PM_OPS.

Let's also get rid of some ifdefs while at it and replace them with
__maybe_unused as SET_RUNTIME_PM_OPS and SET_NOIRQ_SYSTEM_SLEEP_PM_OPS
already deal with the various PM Kconfig options.

Reported-by: Keerthy &lt;j-keerthy@ti.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Acked-by: Vignesh R &lt;vigneshr@ti.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)</title>
<updated>2019-02-12T18:47:11+00:00</updated>
<author>
<name>Fabrizio Castro</name>
<email>fabrizio.castro@bp.renesas.com</email>
</author>
<published>2018-12-13T20:22:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae93f5f803ae0fa08ad95dd5d1c88de59a17e033'/>
<id>ae93f5f803ae0fa08ad95dd5d1c88de59a17e033</id>
<content type='text'>
[ Upstream commit 51243b73455f2d12cb82abffa7bc9028aec656e0 ]

Similarly to R-Car E3, RZ/G2E doesn't come with automatic
transmission registers, as such it is not considered compatible
with the existing fallback bindings.

Add SoC specific binding compatibility to allow for later
support for automatic transmission.

Signed-off-by: Fabrizio Castro &lt;fabrizio.castro@bp.renesas.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 51243b73455f2d12cb82abffa7bc9028aec656e0 ]

Similarly to R-Car E3, RZ/G2E doesn't come with automatic
transmission registers, as such it is not considered compatible
with the existing fallback bindings.

Add SoC specific binding compatibility to allow for later
support for automatic transmission.

Signed-off-by: Fabrizio Castro &lt;fabrizio.castro@bp.renesas.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c-axxia: check for error conditions first</title>
<updated>2019-02-12T18:47:09+00:00</updated>
<author>
<name>Adamski, Krzysztof (Nokia - PL/Wroclaw)</name>
<email>krzysztof.adamski@nokia.com</email>
</author>
<published>2018-12-10T15:01:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b5c21b7e31308c4204778268576bc4ca593f72ba'/>
<id>b5c21b7e31308c4204778268576bc4ca593f72ba</id>
<content type='text'>
[ Upstream commit 4f5c85fe3a60ace555d09898166af372547f97fc ]

It was observed that when using seqentional mode contrary to the
documentation, the SS bit (which is supposed to only be set if
automatic/sequence command completed normally), is sometimes set
together with NA (NAK in address phase) causing transfer to falsely be
considered successful.

My assumption is that this does not happen during manual mode since the
controller is stopping its work the moment it sets NA/ND bit in status
register. This is not the case in Automatic/Sequentional mode where it
is still working to send STOP condition and the actual status we get
depends on the time when the ISR is run.

This patch changes the order of checking status bits in ISR - error
conditions are checked first and only if none of them occurred, the
transfer may be considered successful. This is required to introduce
using of sequentional mode in next patch.

Signed-off-by: Krzysztof Adamski &lt;krzysztof.adamski@nokia.com&gt;
Reviewed-by: Alexander Sverdlin &lt;alexander.sverdlin@nokia.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4f5c85fe3a60ace555d09898166af372547f97fc ]

It was observed that when using seqentional mode contrary to the
documentation, the SS bit (which is supposed to only be set if
automatic/sequence command completed normally), is sometimes set
together with NA (NAK in address phase) causing transfer to falsely be
considered successful.

My assumption is that this does not happen during manual mode since the
controller is stopping its work the moment it sets NA/ND bit in status
register. This is not the case in Automatic/Sequentional mode where it
is still working to send STOP condition and the actual status we get
depends on the time when the ISR is run.

This patch changes the order of checking status bits in ISR - error
conditions are checked first and only if none of them occurred, the
transfer may be considered successful. This is required to introduce
using of sequentional mode in next patch.

Signed-off-by: Krzysztof Adamski &lt;krzysztof.adamski@nokia.com&gt;
Reviewed-by: Alexander Sverdlin &lt;alexander.sverdlin@nokia.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: sh_mobile: add support for r8a77990 (R-Car E3)</title>
<updated>2019-02-12T18:47:03+00:00</updated>
<author>
<name>Simon Horman</name>
<email>horms+renesas@verge.net.au</email>
</author>
<published>2018-11-21T12:09:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8543f5fce30f2ce0c05fe929be2f4a1a36961596'/>
<id>8543f5fce30f2ce0c05fe929be2f4a1a36961596</id>
<content type='text'>
[ Upstream commit 5eb316e636eb298c204f5b368526d4480b63c0ba ]

Add support for the IIC code for the r8a77990 (R-Car E3).

It is not considered compatible with existing fallback bindings
due to the documented absence of automatic transmission registers.

These registers are currently not used by the driver and
thus the provides the same behaviour for "renesas,iic-r8a77990" and
"renesas,rcar-gen3-iic". The point of declaring incompatibility is
to allow for automatic transmission register support to be added to
"renesas,iic-r8a77990" and "renesas,rcar-gen3-iic" in future.

Signed-off-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5eb316e636eb298c204f5b368526d4480b63c0ba ]

Add support for the IIC code for the r8a77990 (R-Car E3).

It is not considered compatible with existing fallback bindings
due to the documented absence of automatic transmission registers.

These registers are currently not used by the driver and
thus the provides the same behaviour for "renesas,iic-r8a77990" and
"renesas,rcar-gen3-iic". The point of declaring incompatibility is
to allow for automatic transmission register support to be added to
"renesas,iic-r8a77990" and "renesas,rcar-gen3-iic" in future.

Signed-off-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: dev: prevent adapter retries and timeout being set as minus value</title>
<updated>2019-01-16T21:04:34+00:00</updated>
<author>
<name>Yi Zeng</name>
<email>yizeng@asrmicro.com</email>
</author>
<published>2019-01-09T07:33:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fca4eb31e09688989f1a6d023131931a14387183'/>
<id>fca4eb31e09688989f1a6d023131931a14387183</id>
<content type='text'>
commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream.

If adapter-&gt;retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter-&gt;algo-&gt;master_xfer and adapter-&gt;algo-&gt;smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter-&gt;timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng &lt;yizeng@asrmicro.com&gt;
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream.

If adapter-&gt;retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter-&gt;algo-&gt;master_xfer and adapter-&gt;algo-&gt;smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter-&gt;timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng &lt;yizeng@asrmicro.com&gt;
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: uniphier-f: fix violation of tLOW requirement for Fast-mode</title>
<updated>2018-12-21T13:15:24+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2018-12-06T03:55:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cab9d27671db270b9fb8f4ed5d3a52cbc94c6438'/>
<id>cab9d27671db270b9fb8f4ed5d3a52cbc94c6438</id>
<content type='text'>
[ Upstream commit ece27a337d42a3197935711997f2880f0957ed7e ]

Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW &gt;= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ece27a337d42a3197935711997f2880f0957ed7e ]

Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW &gt;= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: uniphier: fix violation of tLOW requirement for Fast-mode</title>
<updated>2018-12-21T13:15:24+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2018-12-06T03:55:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb296b2d315bcfaabe9dcd7c43b6795f1fd0f07a'/>
<id>eb296b2d315bcfaabe9dcd7c43b6795f1fd0f07a</id>
<content type='text'>
[ Upstream commit 8469636ab5d8c77645b953746c10fda6983a8830 ]

Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW &gt;= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8469636ab5d8c77645b953746c10fda6983a8830 ]

Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW &gt;= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: scmi: Fix probe error on devices with an empty SMB0001 ACPI device node</title>
<updated>2018-12-21T13:15:24+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2018-11-21T09:19:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9d5db5becd74e2d968d846cf0818c0e3ddbad3d6'/>
<id>9d5db5becd74e2d968d846cf0818c0e3ddbad3d6</id>
<content type='text'>
[ Upstream commit 0544ee4b1ad574aec3b6379af5f5cdee42840971 ]

Some AMD based HP laptops have a SMB0001 ACPI device node which does not
define any methods.

This leads to the following error in dmesg:

[    5.222731] cmi: probe of SMB0001:00 failed with error -5

This commit makes acpi_smbus_cmi_add() return -ENODEV instead in this case
silencing the error. In case of a failure of the i2c_add_adapter() call
this commit now propagates the error from that call instead of -EIO.

Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0544ee4b1ad574aec3b6379af5f5cdee42840971 ]

Some AMD based HP laptops have a SMB0001 ACPI device node which does not
define any methods.

This leads to the following error in dmesg:

[    5.222731] cmi: probe of SMB0001:00 failed with error -5

This commit makes acpi_smbus_cmi_add() return -ENODEV instead in this case
silencing the error. In case of a failure of the i2c_add_adapter() call
this commit now propagates the error from that call instead of -EIO.

Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: axxia: properly handle master timeout</title>
<updated>2018-12-21T13:15:24+00:00</updated>
<author>
<name>Adamski, Krzysztof (Nokia - PL/Wroclaw)</name>
<email>krzysztof.adamski@nokia.com</email>
</author>
<published>2018-11-16T13:24:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9be9c23a507a52b864e8f1d9741d99fbc3572d59'/>
<id>9be9c23a507a52b864e8f1d9741d99fbc3572d59</id>
<content type='text'>
[ Upstream commit 6c7f25cae54b840302e4f1b371dbf318fbf09ab2 ]

According to Intel (R) Axxia TM Lionfish Communication Processor
Peripheral Subsystem Hardware Reference Manual, the AXXIA I2C module
have a programmable Master Wait Timer, which among others, checks the
time between commands send in manual mode. When a timeout (25ms) passes,
TSS bit is set in Master Interrupt Status register and a Stop command is
issued by the hardware.

The axxia_i2c_xfer(), does not properly handle this situation, however.
For each message a separate axxia_i2c_xfer_msg() is called and this
function incorrectly assumes that any interrupt might happen only when
waiting for completion. This is mostly correct but there is one
exception - a master timeout can trigger if enough time has passed
between individual transfers. It will, by definition, happen between
transfers when the interrupts are disabled by the code. If that happens,
the hardware issues Stop command.

The interrupt indicating timeout will not be triggered as soon as we
enable them since the Master Interrupt Status is cleared when master
mode is entered again (which happens before enabling irqs) meaning this
error is lost and the transfer is continued even though the Stop was
issued on the bus. The subsequent operations completes without error but
a bogus value (0xFF in case of read) is read as the client device is
confused because aborted transfer. No error is returned from
master_xfer() making caller believe that a valid value was read.

To fix the problem, the TSS bit (indicating timeout) in Master Interrupt
Status register is checked before each transfer. If it is set, there was
a timeout before this transfer and (as described above) the hardware
already issued Stop command so the transaction should be aborted thus
-ETIMEOUT is returned from the master_xfer() callback. In order to be
sure no timeout was issued we can't just read the status just before
starting new transaction as there will always be a small window of time
(few CPU cycles at best) where this might still happen. For this reason
we have to temporally disable the timer before checking for TSS bit.
Disabling it will, however, clear the TSS bit so in order to preserve
that information, we have to read it in ISR so we have to ensure that
the TSS interrupt is not masked between transfers of one transaction.
There is no need to call bus recovery or controller reinitialization if
that happens so it's skipped.

Signed-off-by: Krzysztof Adamski &lt;krzysztof.adamski@nokia.com&gt;
Reviewed-by: Alexander Sverdlin &lt;alexander.sverdlin@nokia.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6c7f25cae54b840302e4f1b371dbf318fbf09ab2 ]

According to Intel (R) Axxia TM Lionfish Communication Processor
Peripheral Subsystem Hardware Reference Manual, the AXXIA I2C module
have a programmable Master Wait Timer, which among others, checks the
time between commands send in manual mode. When a timeout (25ms) passes,
TSS bit is set in Master Interrupt Status register and a Stop command is
issued by the hardware.

The axxia_i2c_xfer(), does not properly handle this situation, however.
For each message a separate axxia_i2c_xfer_msg() is called and this
function incorrectly assumes that any interrupt might happen only when
waiting for completion. This is mostly correct but there is one
exception - a master timeout can trigger if enough time has passed
between individual transfers. It will, by definition, happen between
transfers when the interrupts are disabled by the code. If that happens,
the hardware issues Stop command.

The interrupt indicating timeout will not be triggered as soon as we
enable them since the Master Interrupt Status is cleared when master
mode is entered again (which happens before enabling irqs) meaning this
error is lost and the transfer is continued even though the Stop was
issued on the bus. The subsequent operations completes without error but
a bogus value (0xFF in case of read) is read as the client device is
confused because aborted transfer. No error is returned from
master_xfer() making caller believe that a valid value was read.

To fix the problem, the TSS bit (indicating timeout) in Master Interrupt
Status register is checked before each transfer. If it is set, there was
a timeout before this transfer and (as described above) the hardware
already issued Stop command so the transaction should be aborted thus
-ETIMEOUT is returned from the master_xfer() callback. In order to be
sure no timeout was issued we can't just read the status just before
starting new transaction as there will always be a small window of time
(few CPU cycles at best) where this might still happen. For this reason
we have to temporally disable the timer before checking for TSS bit.
Disabling it will, however, clear the TSS bit so in order to preserve
that information, we have to read it in ISR so we have to ensure that
the TSS interrupt is not masked between transfers of one transaction.
There is no need to call bus recovery or controller reinitialization if
that happens so it's skipped.

Signed-off-by: Krzysztof Adamski &lt;krzysztof.adamski@nokia.com&gt;
Reviewed-by: Alexander Sverdlin &lt;alexander.sverdlin@nokia.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: rcar: check bus state before reinitializing</title>
<updated>2018-12-21T13:15:12+00:00</updated>
<author>
<name>Wolfram Sang</name>
<email>wsa+renesas@sang-engineering.com</email>
</author>
<published>2018-11-13T11:15:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b288daf8e1da57ecc94d25dcf43bf32405be6a2e'/>
<id>b288daf8e1da57ecc94d25dcf43bf32405be6a2e</id>
<content type='text'>
[ Upstream commit 0b57436f15bf40e432487086c4f2d01fd3529393 ]

We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.

Credits go to the Renesas BSP team for suggesting this change.

Reported-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
Fixes: ae481cc13965 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0b57436f15bf40e432487086c4f2d01fd3529393 ]

We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.

Credits go to the Renesas BSP team for suggesting this change.

Reported-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
Fixes: ae481cc13965 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
