linux-toradex.git/drivers/tty, branch v5.18-rc5 Linux kernel for Apalis and Colibri modules tty: n_gsm: fix sometimes uninitialized warning in gsm_dlci_modem_output() 2022-04-26T06:09:46+00:00 Daniel Starke daniel.starke@siemens.com 2022-04-25T10:47:26+00:00 19317433057dc1f2ca9a975e4e6b547282c2a5ef 'size' may be used uninitialized in gsm_dlci_modem_output() if called with an adaption that is neither 1 nor 2. The function is currently only called by gsm_modem_upd_via_data() and only for adaption 2. Properly handle every invalid case by returning -EINVAL to silence the compiler warning and avoid future regressions. Fixes: c19ffe00fed6 ("tty: n_gsm: fix invalid use of MSC in advanced option") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
'size' may be used uninitialized in gsm_dlci_modem_output() if called with
an adaption that is neither 1 nor 2. The function is currently only called
by gsm_modem_upd_via_data() and only for adaption 2.
Properly handle every invalid case by returning -EINVAL to silence the
compiler warning and avoid future regressions.

Fixes: c19ffe00fed6 ("tty: n_gsm: fix invalid use of MSC in advanced option")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250: Correct the clock for EndRun PTP/1588 PCIe device 2022-04-22T14:38:10+00:00 Maciej W. Rozycki macro@orcam.me.uk 2022-04-18T15:27:16+00:00 637674fa40059cddcc3ad2212728965072f62ea3 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 is therefore driven by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock. The clock rate is divided by the oversampling rate of 16 as it is supplied to the baud rate generator, yielding the baud base of 3906250. Replace the incorrect baud base of 4000000 with the right value of 3906250 then, complementing commit 6cbe45d8ac93 ("serial: 8250: Correct the clock for OxSemi PCIe devices"). Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable <stable@kernel.org> Fixes: 1bc8cde46a159 ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 is therefore driven by a fixed 62.5MHz clock
input derived from the 100MHz PCI Express clock.  The clock rate is
divided by the oversampling rate of 16 as it is supplied to the baud
rate generator, yielding the baud base of 3906250.

Replace the incorrect baud base of 4000000 with the right value of
3906250 then, complementing commit 6cbe45d8ac93 ("serial: 8250: Correct
the clock for OxSemi PCIe devices").

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable <stable@kernel.org>
Fixes: 1bc8cde46a159 ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250: Also set sticky MCR bits in console restoration 2022-04-22T14:38:06+00:00 Maciej W. Rozycki macro@orcam.me.uk 2022-04-18T15:27:10+00:00 6e6eebdf5e2455f089ccd000754a0deaeb79af82 Sticky MCR bits are lost in console restoration if console suspending has been disabled. This currently affects the AFE bit, which works in combination with RTS which we set, so we want to make sure the UART retains control of its FIFO where previously requested. Also specific drivers may need other bits in the future. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Cc: stable@vger.kernel.org # v4.0+ Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Sticky MCR bits are lost in console restoration if console suspending
has been disabled.  This currently affects the AFE bit, which works in
combination with RTS which we set, so we want to make sure the UART
retains control of its FIFO where previously requested.  Also specific
drivers may need other bits in the future.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend")
Cc: stable@vger.kernel.org # v4.0+
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: n_gsm: fix software flow control handling 2022-04-22T14:37:44+00:00 Daniel Starke daniel.starke@siemens.com 2022-04-22T07:10:25+00:00 f4f7d63287217ba25e5c80f5faae5e4f7118790e 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 5.4.8.1 states that XON/XOFF characters shall be used instead of Fcon/Fcoff command in advanced option mode to handle flow control. Chapter 5.4.8.2 describes how XON/XOFF characters shall be handled. Basic option mode only used Fcon/Fcoff commands and no XON/XOFF characters. These are treated as data bytes here. The current implementation uses the gsm_mux field 'constipated' to handle flow control from the remote peer and the gsm_dlci field 'constipated' to handle flow control from each DLCI. The later is unrelated to this patch. The gsm_mux field is correctly set for Fcon/Fcoff commands in gsm_control_message(). However, the same is not true for XON/XOFF characters in gsm1_receive(). Disable software flow control handling in the tty to allow explicit handling by n_gsm. Add the missing handling in advanced option mode for gsm_mux in gsm1_receive() to comply with the standard. This patch depends on the following commit: Commit 8838b2af23ca ("tty: n_gsm: fix SW flow control encoding/handling") Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 5.4.8.1 states that XON/XOFF characters
shall be used instead of Fcon/Fcoff command in advanced option mode to
handle flow control. Chapter 5.4.8.2 describes how XON/XOFF characters
shall be handled. Basic option mode only used Fcon/Fcoff commands and no
XON/XOFF characters. These are treated as data bytes here.
The current implementation uses the gsm_mux field 'constipated' to handle
flow control from the remote peer and the gsm_dlci field 'constipated' to
handle flow control from each DLCI. The later is unrelated to this patch.
The gsm_mux field is correctly set for Fcon/Fcoff commands in
gsm_control_message(). However, the same is not true for XON/XOFF
characters in gsm1_receive().
Disable software flow control handling in the tty to allow explicit
handling by n_gsm.
Add the missing handling in advanced option mode for gsm_mux in
gsm1_receive() to comply with the standard.

This patch depends on the following commit:
Commit 8838b2af23ca ("tty: n_gsm: fix SW flow control encoding/handling")

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: n_gsm: fix invalid use of MSC in advanced option 2022-04-22T14:37:44+00:00 Daniel Starke daniel.starke@siemens.com 2022-04-22T07:10:24+00:00 c19ffe00fed6bb423d81406d2a7e5793074c7d83 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 5.4.6.3.7 states that the Modem Status Command (MSC) shall only be used if the basic option was chosen. The current implementation uses MSC frames even if advanced option was chosen to inform the peer about modem line state updates. A standard conform peer may choose to discard these frames in advanced option mode. Furthermore, gsmtty_modem_update() is not part of the 'tty_operations' functions despite its name. Rename gsmtty_modem_update() to gsm_modem_update() to clarify this. Split its function into gsm_modem_upd_via_data() and gsm_modem_upd_via_msc() depending on the encoding and adaption. Introduce gsm_dlci_modem_output() as adaption of gsm_dlci_data_output() to encode and queue empty frames in advanced option mode. Use it in gsm_modem_upd_via_data(). gsm_modem_upd_via_msc() is based on the initial gsmtty_modem_update() function which used only MSC frames to update modem states. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 5.4.6.3.7 states that the Modem Status
Command (MSC) shall only be used if the basic option was chosen.
The current implementation uses MSC frames even if advanced option was
chosen to inform the peer about modem line state updates. A standard
conform peer may choose to discard these frames in advanced option mode.
Furthermore, gsmtty_modem_update() is not part of the 'tty_operations'
functions despite its name.
Rename gsmtty_modem_update() to gsm_modem_update() to clarify this. Split
its function into gsm_modem_upd_via_data() and gsm_modem_upd_via_msc()
depending on the encoding and adaption. Introduce gsm_dlci_modem_output()
as adaption of gsm_dlci_data_output() to encode and queue empty frames in
advanced option mode. Use it in gsm_modem_upd_via_data().
gsm_modem_upd_via_msc() is based on the initial gsmtty_modem_update()
function which used only MSC frames to update modem states.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: n_gsm: fix broken virtual tty handling 2022-04-22T14:37:44+00:00 Daniel Starke daniel.starke@siemens.com 2022-04-22T07:10:23+00:00 a8c5b8255f8a9acd58a4b15ff1c14cd6effd114b Dynamic virtual tty registration was introduced to allow the user to handle these cases with uevent rules. The following commits relate to this: Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester") Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()") However, the following behavior can be seen with this implementation: - n_gsm ldisc is activated via ioctl - all configuration parameters are set to their default value (initiator=0) - the mux gets activated and attached and gsmtty0 is being registered in in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control channel) - the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator - this re-attaches the n_gsm mux - no new gsmtty devices are registered in gsmld_attach_gsm() because the mux is already active - the initiator side registered only the control channel as gsmtty0 (which should never happen) and no user channel tty The commits above make it impossible to operate the initiator side as no user channel tty is or will be available. On the other hand, this behavior will make it also impossible to allow DLCI parameter negotiation on responder side in the future. The responder side first needs to provide a device for the application before the application can set its parameters of the associated DLCI via ioctl. Note that the user application is still able to detect a link establishment without relaying to uevent by waiting for DTR open on responder side. This is the same behavior as on a physical serial interface. And on initiator side a tty hangup can be detected if a link establishment request failed. Revert the commits above completely to always register all user channels and no control channel after mux attachment. No other changes are made. Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Dynamic virtual tty registration was introduced to allow the user to handle
these cases with uevent rules. The following commits relate to this:
Commit 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Commit 0b91b5332368 ("tty: n_gsm: Save dlci address open status when config requester")
Commit 46292622ad73 ("tty: n_gsm: clean up indenting in gsm_queue()")

However, the following behavior can be seen with this implementation:
- n_gsm ldisc is activated via ioctl
- all configuration parameters are set to their default value (initiator=0)
- the mux gets activated and attached and gsmtty0 is being registered in
  in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control
  channel)
- the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator
- this re-attaches the n_gsm mux
- no new gsmtty devices are registered in gsmld_attach_gsm() because the
  mux is already active
- the initiator side registered only the control channel as gsmtty0
  (which should never happen) and no user channel tty

The commits above make it impossible to operate the initiator side as no
user channel tty is or will be available.
On the other hand, this behavior will make it also impossible to allow DLCI
parameter negotiation on responder side in the future. The responder side
first needs to provide a device for the application before the application
can set its parameters of the associated DLCI via ioctl.
Note that the user application is still able to detect a link establishment
without relaying to uevent by waiting for DTR open on responder side. This
is the same behavior as on a physical serial interface. And on initiator
side a tty hangup can be detected if a link establishment request failed.

Revert the commits above completely to always register all user channels
and no control channel after mux attachment. No other changes are made.

Fixes: 5b87686e3203 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "serial: sc16is7xx: Clear RS485 bits in the shutdown" 2022-04-22T14:37:00+00:00 Hui Wang hui.wang@canonical.com 2022-04-18T09:43:39+00:00 41c606879f89623dd5269eaffea640b915e9e17c This reverts commit 927728a34f11b5a27f4610bdb7068317d6fdc72a. Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port should always work in RS485 mode. If users want the port to leave RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED. So here we shouldn't clear the RS485 bits in the shutdown(). Fixes: 927728a34f11 ("serial: sc16is7xx: Clear RS485 bits in the shutdown") Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This reverts commit 927728a34f11b5a27f4610bdb7068317d6fdc72a.

Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port
should always work in RS485 mode. If users want the port to leave
RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED.

So here we shouldn't clear the RS485 bits in the shutdown().

Fixes: 927728a34f11 ("serial: sc16is7xx: Clear RS485 bits in the shutdown")
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: n_gsm: fix missing update of modem controls after DLCI open 2022-04-20T14:52:25+00:00 Daniel Starke daniel.starke@siemens.com 2022-04-20T10:13:44+00:00 48473802506d2d6151f59e0e764932b33b53cb3b Currently the peer is not informed about the initial state of the modem control lines after a new DLCI has been opened. Fix this by sending the initial modem control line states after DLCI open. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250: Fix runtime PM for start_tx() for empty buffer 2022-04-15T09:42:09+00:00 Tony Lindgren tony@atomide.com 2022-04-11T11:16:57+00:00 cc994bb97587787b8f0c094a9bc6945d82075b1d Commit 932d596378b0 ("serial: 8250: Return early in .start_tx() if there are no chars to send") caused a regression where the drivers implementing runtime PM stopped idling. This is because serial8250_rpm_put_tx() is now unbalanced on early return, it normally gets called at __stop_tx(). Fixes: 932d596378b0 ("serial: 8250: Return early in .start_tx() if there are no chars to send") Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Johan Hovold <johan@kernel.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20220411111657.16744-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit 932d596378b0 ("serial: 8250: Return early in .start_tx() if there
are no chars to send") caused a regression where the drivers implementing
runtime PM stopped idling. This is because serial8250_rpm_put_tx() is now
unbalanced on early return, it normally gets called at __stop_tx().

Fixes: 932d596378b0 ("serial: 8250: Return early in .start_tx() if there are no chars to send")
Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20220411111657.16744-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: imx: fix overrun interrupts in DMA mode 2022-04-15T09:41:58+00:00 Johan Hovold johan@kernel.org 2022-04-11T08:19:57+00:00 3ee82c6e41f3d2212647ce0bc5a05a0f69097824 Commit 76821e222c18 ("serial: imx: ensure that RX irqs are off if RX is off") accidentally enabled overrun interrupts unconditionally when deferring DMA enable until after the receiver has been enabled during startup. Fix this by using the DMA-initialised instead of DMA-enabled flag to determine whether overrun interrupts should be enabled. Note that overrun interrupts are already accounted for in imx_uart_clear_rx_errors() when using DMA since commit 41d98b5da92f ("serial: imx-serial - update RX error counters when DMA is used"). Fixes: 76821e222c18 ("serial: imx: ensure that RX irqs are off if RX is off") Cc: stable@vger.kernel.org # 4.17 Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20220411081957.7846-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit 76821e222c18 ("serial: imx: ensure that RX irqs are off if RX is
off") accidentally enabled overrun interrupts unconditionally when
deferring DMA enable until after the receiver has been enabled during
startup.

Fix this by using the DMA-initialised instead of DMA-enabled flag to
determine whether overrun interrupts should be enabled.

Note that overrun interrupts are already accounted for in
imx_uart_clear_rx_errors() when using DMA since commit 41d98b5da92f
("serial: imx-serial - update RX error counters when DMA is used").

Fixes: 76821e222c18 ("serial: imx: ensure that RX irqs are off if RX is off")
Cc: stable@vger.kernel.org      # 4.17
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220411081957.7846-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>