<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/tty, branch linux-5.18.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>tty: 8250: Add support for Brainboxes PX cards.</title>
<updated>2022-08-17T12:42:23+00:00</updated>
<author>
<name>Cameron Williams</name>
<email>cang1@live.co.uk</email>
</author>
<published>2022-07-11T15:35:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c68beda796bf45a65122bd4c861d6067604625e6'/>
<id>c68beda796bf45a65122bd4c861d6067604625e6</id>
<content type='text'>
[ Upstream commit ef5a03a26c87a760bc3d86b5af7b773e82f8b1b7 ]

Add support for some of the Brainboxes PCIe (PX) range of
serial cards, including the PX-101, PX-235/PX-246,
PX-203/PX-257, PX-260/PX-701, PX-310, PX-313,
PX-320/PX-324/PX-376/PX-387, PX-335/PX-346, PX-368, PX-420,
PX-803 and PX-846.

Signed-off-by: Cameron Williams &lt;cang1@live.co.uk&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/AM5PR0202MB2564669252BDC59BF55A6E87C4879@AM5PR0202MB2564.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 ef5a03a26c87a760bc3d86b5af7b773e82f8b1b7 ]

Add support for some of the Brainboxes PCIe (PX) range of
serial cards, including the PX-101, PX-235/PX-246,
PX-203/PX-257, PX-260/PX-701, PX-310, PX-313,
PX-320/PX-324/PX-376/PX-387, PX-335/PX-346, PX-368, PX-420,
PX-803 and PX-846.

Signed-off-by: Cameron Williams &lt;cang1@live.co.uk&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/AM5PR0202MB2564669252BDC59BF55A6E87C4879@AM5PR0202MB2564.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250: Add proper clock handling for OxSemi PCIe devices</title>
<updated>2022-08-17T12:42:23+00:00</updated>
<author>
<name>Maciej W. Rozycki</name>
<email>macro@orcam.me.uk</email>
</author>
<published>2022-04-18T15:27:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9ac561ad8fd75f6cf01f66b7e969e351a1e99887'/>
<id>9ac561ad8fd75f6cf01f66b7e969e351a1e99887</id>
<content type='text'>
[ Upstream commit 366f6c955d4d1a5125ffcd6875ead26a3c7a2a1c ]

Oxford Semiconductor PCIe (Tornado) 950 serial port devices are driven
by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock.

We currently drive the device using its default oversampling rate of 16
and the clock prescaler disabled, consequently yielding the baud base of
3906250.  This base is inadequate for some of the high-speed baud rates
such as 460800bps, for which the closest rate possible can be obtained
by dividing the baud base by 8, yielding the baud rate of 488281.25bps,
which is off by 5.9638%.  This is enough for data communication to break
with the remote end talking actual 460800bps, where missed stop bits
have been observed.

We can do better however, by taking advantage of a reduced oversampling
rate, which can be set to any integer value from 4 to 16 inclusive by
programming the TCR register, and by using the clock prescaler, which
can be set to any value from 1 to 63.875 in increments of 0.125 in the
CPR/CPR2 register pair.  The prescaler has to be explicitly enabled
though by setting bit 7 in the MCR or otherwise it is bypassed (in the
enhanced mode that we enable) as if the value of 1 was used.

Make use of these features then as follows:

- Set the baud base to 15625000, reflecting the minimum oversampling
  rate of 4 with the clock prescaler and divisor both set to 1.

- Override the `set_mctrl' and set the MCR shadow there so as to have
  MCR[7] always set and have the 8250 core propagate these settings.

- Override the `get_divisor' handler and determine a good combination of
  parameters by using a lookup table with predetermined value pairs of
  the oversampling rate and the clock prescaler and finding a pair that
  divides the input clock such that the quotient, when rounded to the
  nearest integer, deviates the least from the exact result.  Calculate
  the clock divisor accordingly.

  Scale the resulting oversampling rate (only by powers of two) if
  possible so as to maximise it, reducing the divisor accordingly, and
  avoid a divisor overflow for very low baud rates by scaling the
  oversampling rate and/or the prescaler even if that causes some
  accuracy loss.

  Also handle the historic spd_cust feature so as to allow one to set
  all the three parameters manually to arbitrary values, by keeping the
  low 16 bits for the divisor and then putting TCR in bits 19:16 and
  CPR/CPR2 in bits 28:20, sanitising the bit pattern supplied such as
  to clamp CPR/CPR2 values between 0.000 and 0.875 inclusive to 33.875.
  This preserves compatibility with any existing setups, that is where
  requesting a custom divisor that only has any bits set among the low
  16 the oversampling rate of 16 and the clock prescaler of 33.875 will
  be used as with the original 8250.

  Finally abuse the `frac' argument to store the determined bit patterns
  for the TCR, CPR and CPR2 registers.

- Override the `set_divisor' handler so as to set the TCR, CPR and CPR2
  registers from the `frac' value supplied.  Set the divisor as usual.

With the baud base set to 15625000 and the unsigned 16-bit UART_DIV_MAX
limitation imposed by `serial8250_get_baud_rate' standard baud rates
below 300bps become unavailable in the regular way, e.g. the rate of
200bps requires the baud base to be divided by 78125 and that is beyond
the unsigned 16-bit range.  The historic spd_cust feature can still be
used to obtain such rates if so required.

See Documentation/tty/device_drivers/oxsemi-tornado.rst for more details.

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181519450.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 366f6c955d4d1a5125ffcd6875ead26a3c7a2a1c ]

Oxford Semiconductor PCIe (Tornado) 950 serial port devices are driven
by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock.

We currently drive the device using its default oversampling rate of 16
and the clock prescaler disabled, consequently yielding the baud base of
3906250.  This base is inadequate for some of the high-speed baud rates
such as 460800bps, for which the closest rate possible can be obtained
by dividing the baud base by 8, yielding the baud rate of 488281.25bps,
which is off by 5.9638%.  This is enough for data communication to break
with the remote end talking actual 460800bps, where missed stop bits
have been observed.

We can do better however, by taking advantage of a reduced oversampling
rate, which can be set to any integer value from 4 to 16 inclusive by
programming the TCR register, and by using the clock prescaler, which
can be set to any value from 1 to 63.875 in increments of 0.125 in the
CPR/CPR2 register pair.  The prescaler has to be explicitly enabled
though by setting bit 7 in the MCR or otherwise it is bypassed (in the
enhanced mode that we enable) as if the value of 1 was used.

Make use of these features then as follows:

- Set the baud base to 15625000, reflecting the minimum oversampling
  rate of 4 with the clock prescaler and divisor both set to 1.

- Override the `set_mctrl' and set the MCR shadow there so as to have
  MCR[7] always set and have the 8250 core propagate these settings.

- Override the `get_divisor' handler and determine a good combination of
  parameters by using a lookup table with predetermined value pairs of
  the oversampling rate and the clock prescaler and finding a pair that
  divides the input clock such that the quotient, when rounded to the
  nearest integer, deviates the least from the exact result.  Calculate
  the clock divisor accordingly.

  Scale the resulting oversampling rate (only by powers of two) if
  possible so as to maximise it, reducing the divisor accordingly, and
  avoid a divisor overflow for very low baud rates by scaling the
  oversampling rate and/or the prescaler even if that causes some
  accuracy loss.

  Also handle the historic spd_cust feature so as to allow one to set
  all the three parameters manually to arbitrary values, by keeping the
  low 16 bits for the divisor and then putting TCR in bits 19:16 and
  CPR/CPR2 in bits 28:20, sanitising the bit pattern supplied such as
  to clamp CPR/CPR2 values between 0.000 and 0.875 inclusive to 33.875.
  This preserves compatibility with any existing setups, that is where
  requesting a custom divisor that only has any bits set among the low
  16 the oversampling rate of 16 and the clock prescaler of 33.875 will
  be used as with the original 8250.

  Finally abuse the `frac' argument to store the determined bit patterns
  for the TCR, CPR and CPR2 registers.

- Override the `set_divisor' handler so as to set the TCR, CPR and CPR2
  registers from the `frac' value supplied.  Set the divisor as usual.

With the baud base set to 15625000 and the unsigned 16-bit UART_DIV_MAX
limitation imposed by `serial8250_get_baud_rate' standard baud rates
below 300bps become unavailable in the regular way, e.g. the rate of
200bps requires the baud base to be divided by 78125 and that is beyond
the unsigned 16-bit range.  The historic spd_cust feature can still be
used to obtain such rates if so required.

See Documentation/tty/device_drivers/oxsemi-tornado.rst for more details.

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181519450.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250: Fold EndRun device support into OxSemi Tornado code</title>
<updated>2022-08-17T12:42:22+00:00</updated>
<author>
<name>Maciej W. Rozycki</name>
<email>macro@orcam.me.uk</email>
</author>
<published>2022-04-18T15:27:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=30f92d669ce94823245c5485ee111e0e8db50599'/>
<id>30f92d669ce94823245c5485ee111e0e8db50599</id>
<content type='text'>
[ Upstream commit 1f32c65bad24b9787d3e52843de375430e3df822 ]

The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and uses the same sequence to determine the
number of ports available.  Despite that we have duplicate code
specific to the EndRun device.

Remove redundant code then and factor out OxSemi Tornado device
detection.

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181516220.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 1f32c65bad24b9787d3e52843de375430e3df822 ]

The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and uses the same sequence to determine the
number of ports available.  Despite that we have duplicate code
specific to the EndRun device.

Remove redundant code then and factor out OxSemi Tornado device
detection.

Signed-off-by: Maciej W. Rozycki &lt;macro@orcam.me.uk&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181516220.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: serial: fsl_lpuart: correct the count of break characters</title>
<updated>2022-08-17T12:42:12+00:00</updated>
<author>
<name>Sherry Sun</name>
<email>sherry.sun@nxp.com</email>
</author>
<published>2022-07-25T05:01:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c139aa934b91d1d285842c9adada11a47f452f0a'/>
<id>c139aa934b91d1d285842c9adada11a47f452f0a</id>
<content type='text'>
[ Upstream commit 707f816f25590c20e056b3bd4a17ce69b03fe856 ]

The LPUART can't distinguish between a break signal and a framing error,
so need to count the break characters if there is a framing error and
received data is zero instead of the parity error.

Fixes: 5541a9bacfe5 ("serial: fsl_lpuart: handle break and make sysrq work")
Reviewed-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Sherry Sun &lt;sherry.sun@nxp.com&gt;
Link: https://lore.kernel.org/r/20220725050115.12396-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 707f816f25590c20e056b3bd4a17ce69b03fe856 ]

The LPUART can't distinguish between a break signal and a framing error,
so need to count the break characters if there is a framing error and
received data is zero instead of the parity error.

Fixes: 5541a9bacfe5 ("serial: fsl_lpuart: handle break and make sysrq work")
Reviewed-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Sherry Sun &lt;sherry.sun@nxp.com&gt;
Link: https://lore.kernel.org/r/20220725050115.12396-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()</title>
<updated>2022-08-17T12:42:12+00:00</updated>
<author>
<name>Guo Mengqi</name>
<email>guomengqi3@huawei.com</email>
</author>
<published>2022-07-15T02:33:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b6fe0365f1f1f74a0510179a1d95b40c83302e0d'/>
<id>b6fe0365f1f1f74a0510179a1d95b40c83302e0d</id>
<content type='text'>
[ Upstream commit b9f1736e475dba0d6da48fdcb831248ab1597886 ]

The error path when get clock frequency fails in bcm2835aux_serial
driver does not correctly disable the clock.

This flaw was found using a static analysis tool "Hulk Robot", which
reported the following warning when analyzing linux-next/master:

    drivers/tty/serial/8250/8250_bcm2835aux.c:
    warning: clk_disable_unprepare_missing.cocci

The cocci script checks for the existence of clk_disable_unprepare()
paired with clk_prepare_enable().

Add the missing clk_disable_unprepare() to the error path.

Fixes: fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: Guo Mengqi &lt;guomengqi3@huawei.com&gt;
Link: https://lore.kernel.org/r/20220715023312.37808-1-guomengqi3@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 b9f1736e475dba0d6da48fdcb831248ab1597886 ]

The error path when get clock frequency fails in bcm2835aux_serial
driver does not correctly disable the clock.

This flaw was found using a static analysis tool "Hulk Robot", which
reported the following warning when analyzing linux-next/master:

    drivers/tty/serial/8250/8250_bcm2835aux.c:
    warning: clk_disable_unprepare_missing.cocci

The cocci script checks for the existence of clk_disable_unprepare()
paired with clk_prepare_enable().

Add the missing clk_disable_unprepare() to the error path.

Fixes: fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: Guo Mengqi &lt;guomengqi3@huawei.com&gt;
Link: https://lore.kernel.org/r/20220715023312.37808-1-guomengqi3@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250_bcm7271: Save/restore RTS in suspend/resume</title>
<updated>2022-08-17T12:42:06+00:00</updated>
<author>
<name>Doug Berger</name>
<email>opendmb@gmail.com</email>
</author>
<published>2022-07-14T03:13:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=11f0e52d953526b67130b9d9333fc24054e5a020'/>
<id>11f0e52d953526b67130b9d9333fc24054e5a020</id>
<content type='text'>
[ Upstream commit 3182efd036c1b955403d131258234896cbd9fbeb ]

Commit 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming
from S2") prevented an early enabling of RTS during resume, but it did
not actively restore the RTS state after resume.

Fixes: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2")
Signed-off-by: Doug Berger &lt;opendmb@gmail.com&gt;
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 3182efd036c1b955403d131258234896cbd9fbeb ]

Commit 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming
from S2") prevented an early enabling of RTS during resume, but it did
not actively restore the RTS state after resume.

Fixes: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2")
Signed-off-by: Doug Berger &lt;opendmb@gmail.com&gt;
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: n_gsm: fix missing corner cases in gsmld_poll()</title>
<updated>2022-08-17T12:42:05+00:00</updated>
<author>
<name>Daniel Starke</name>
<email>daniel.starke@siemens.com</email>
</author>
<published>2022-07-07T11:32:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=286bf073d0869624610166873b1a0a5d3f4a7e20'/>
<id>286bf073d0869624610166873b1a0a5d3f4a7e20</id>
<content type='text'>
[ Upstream commit 7e5b4322cde067e1d0f1bf8f490e93f664a7c843 ]

gsmld_poll() currently fails to handle the following corner cases correctly:
- remote party closed the associated tty

Add the missing checks and map those to EPOLLHUP.
Reorder the checks to group them by their reaction.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 7e5b4322cde067e1d0f1bf8f490e93f664a7c843 ]

gsmld_poll() currently fails to handle the following corner cases correctly:
- remote party closed the associated tty

Add the missing checks and map those to EPOLLHUP.
Reorder the checks to group them by their reaction.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: n_gsm: fix flow control handling in tx path</title>
<updated>2022-08-17T12:42:04+00:00</updated>
<author>
<name>Daniel Starke</name>
<email>daniel.starke@siemens.com</email>
</author>
<published>2022-07-07T11:32:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b0c5d7a86701584298bdb4ea076dd71ad618cefb'/>
<id>b0c5d7a86701584298bdb4ea076dd71ad618cefb</id>
<content type='text'>
[ Upstream commit 59ff0680ecbfec742b1e0381e7cc46b41eb06647 ]

The current implementation constipates all transmission paths during flow
control except for flow control frames. However, these may not be located
at the beginning of the transmission queue of the control channel.
Ensure that flow control frames in the transmission queue for the control
channel are always handled even if constipated by skipping through other
messages.

Fixes: 0af021678d5d ("tty: n_gsm: fix deadlock and link starvation in outgoing data path")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 59ff0680ecbfec742b1e0381e7cc46b41eb06647 ]

The current implementation constipates all transmission paths during flow
control except for flow control frames. However, these may not be located
at the beginning of the transmission queue of the control channel.
Ensure that flow control frames in the transmission queue for the control
channel are always handled even if constipated by skipping through other
messages.

Fixes: 0af021678d5d ("tty: n_gsm: fix deadlock and link starvation in outgoing data path")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: n_gsm: fix DM command</title>
<updated>2022-08-17T12:42:04+00:00</updated>
<author>
<name>Daniel Starke</name>
<email>daniel.starke@siemens.com</email>
</author>
<published>2022-07-07T11:32:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d922c8511b2d19367a2a135835596c30acf8cd87'/>
<id>d922c8511b2d19367a2a135835596c30acf8cd87</id>
<content type='text'>
[ Upstream commit 18a948c7d90995d127785e308fa7b701df4c499f ]

n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.3.3 defines the DM response. There exists
no DM command. However, the current implementation incorrectly sends DM as
command in case of unexpected UIH frames in gsm_queue().
Correct this behavior by always sending DM as response.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 18a948c7d90995d127785e308fa7b701df4c499f ]

n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.3.3 defines the DM response. There exists
no DM command. However, the current implementation incorrectly sends DM as
command in case of unexpected UIH frames in gsm_queue().
Correct this behavior by always sending DM as response.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: n_gsm: fix wrong T1 retry count handling</title>
<updated>2022-08-17T12:42:04+00:00</updated>
<author>
<name>Daniel Starke</name>
<email>daniel.starke@siemens.com</email>
</author>
<published>2022-07-07T11:32:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=04ac11f6b604f17e78f0a968047f9c3c1a88ecd4'/>
<id>04ac11f6b604f17e78f0a968047f9c3c1a88ecd4</id>
<content type='text'>
[ Upstream commit f30e10caa80aa1f35508bc17fc302dbbde9a833c ]

n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_dlci_t1() handles this number incorrectly by performing N2 - 1
retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix gsm_dlci_t1() to comply with 3GPP 27.010.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 f30e10caa80aa1f35508bc17fc302dbbde9a833c ]

n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_dlci_t1() handles this number incorrectly by performing N2 - 1
retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix gsm_dlci_t1() to comply with 3GPP 27.010.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke &lt;daniel.starke@siemens.com&gt;
Link: https://lore.kernel.org/r/20220707113223.3685-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
