linux-stable.git/drivers/tty/serial/altera_uart.c, branch linux-5.4.y

serial: altera_uart: fix locking in polling mode

2023-01-18T10:41:23+00:00

[ Upstream commit 1307c5d33cce8a41dd77c2571e4df65a5b627feb ]

Since altera_uart_interrupt() may also be called from
a poll timer in "serving_softirq" context, use
spin_[lock_irqsave|unlock_irqrestore] variants, which
are appropriate for both softirq and hardware interrupt
contexts.

Fixes: 2f8b9c15cd88 ("altera_uart: Add support for polling mode (IRQ-less)")
Signed-off-by: Gabriel Somlo 
Link: https://lore.kernel.org/r/20221122200426.888349-1-gsomlo@gmail.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: altera_uart_{r,t}x_chars() need only uart_port

2023-01-18T10:41:23+00:00

[ Upstream commit 3af44d9bb0539d5fa27d6159d696fda5f3747bff ]

Both altera_uart_{r,t}x_chars() need only uart_port, not altera_uart. So
pass the former from altera_uart_interrupt() directly.

Apart it maybe saves a dereference, this makes the transition of
altera_uart_tx_chars() easier to follow in the next patch.

Cc: Tobias Klauser 
Reviewed-by: Ilpo Järvinen 
Acked-by: Tobias Klauser 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20220920052049.20507-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode")
Signed-off-by: Sasha Levin

tty: serial: clean up stop-tx part in altera_uart_tx_chars()

2023-01-18T10:41:23+00:00

[ Upstream commit d9c128117da41cf4cb0e80ae565b5d3ac79dffac ]

The "stop TX" path in altera_uart_tx_chars() is open-coded, so:
* use uart_circ_empty() to check if the buffer is empty, and
* when true, call altera_uart_stop_tx().

Cc: Tobias Klauser 
Reviewed-by: Ilpo Järvinen 
Acked-by: Tobias Klauser 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20220920052049.20507-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: 1307c5d33cce ("serial: altera_uart: fix locking in polling mode")
Signed-off-by: Sasha Levin

serial: altera: set RRDY flag also without irq

2018-02-28T12:30:09+00:00

The UART can be operated without an irq. In this case a timer is setup
that regularily calls altera_uart_interrupt(). The receiving part
depends on pp->imr having the bit ALTERA_UART_STATUS_RRDY_MSK set,
otherwise altera_uart_rx_chars() is never called. So ensure that the bit
gets set (disguised as ALTERA_UART_CONTROL_RRDY_MSK) by not returning
early from altera_uart_startup() if port->irq is 0.

This doesn't affect the hardware as the ALTERA_UART_CONTROL_RRDY_MSK bit
isn't actually written to the control register.

Signed-off-by: Uwe Kleine-König 
Acked-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

serial: altera: don't enable any irq if the device doesn't feature an irq

2018-02-28T12:30:09+00:00

If the irq line of an altera UART device isn't used to report interrupts
for this device the driver better ensures that this device doesn't pull
this line to active state and so disturb the whatever might be connected
to this line.

Signed-off-by: Uwe Kleine-König 
Acked-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

serial: altera: ensure port->regshift is honored consistently

2018-02-28T12:30:09+00:00

Most register accesses in the altera driver honor port->regshift by
using altera_uart_writel(). There are a few accesses however that were
missed when the driver was converted to use port->regshift and some
others were added later in commit 4d9d7d896d77 ("serial: altera_uart:
add earlycon support").

Fixes: 2780ad42f5fe ("tty: serial: altera_uart: Use port->regshift to store bus shift")
Signed-off-by: Uwe Kleine-König 
Acked-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

tty: serial: Remove redundant license text

2017-11-08T12:08:12+00:00

Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Jiri Slaby 
Cc: Eric Anholt 
Cc: Stefan Wahren 
Cc: Florian Fainelli 
Cc: Ray Jui 
Cc: Scott Branden 
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Joachim Eastwood 
Cc: Matthias Brugger 
Cc: Masahiro Yamada 
Cc: Tobias Klauser 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: Pat Gefre 
Cc: "Guilherme G. Piccoli" 
Cc: Jason Wessel 
Cc: Vladimir Zapolskiy 
Cc: Sylvain Lemieux 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Liviu Dudau 
Cc: Sudeep Holla 
Cc: Lorenzo Pieralisi 
Cc: Andy Gross 
Cc: David Brown 
Cc: "Andreas Färber" 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Kevin Cernekee 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Barry Song 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: Chris Metcalf 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Tony Prisk 
Cc: Michal Simek 
Cc: "Sören Brinkmann" 
Signed-off-by: Greg Kroah-Hartman

tty: add SPDX identifiers to all remaining files in drivers/tty/

2017-11-08T12:08:12+00:00

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Jiri Slaby 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Chris Metcalf 
Cc: Jiri Kosina 
Cc: David Sterba 
Cc: James Hogan 
Cc: Rob Herring 
Cc: Eric Anholt 
Cc: Stefan Wahren 
Cc: Florian Fainelli 
Cc: Ray Jui 
Cc: Scott Branden 
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Joachim Eastwood 
Cc: Matthias Brugger 
Cc: Masahiro Yamada 
Cc: Tobias Klauser 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: "Maciej W. Rozycki" 
Cc: "Uwe Kleine-König" 
Cc: Pat Gefre 
Cc: "Guilherme G. Piccoli" 
Cc: Jason Wessel 
Cc: Vladimir Zapolskiy 
Cc: Sylvain Lemieux 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Liviu Dudau 
Cc: Sudeep Holla 
Cc: Lorenzo Pieralisi 
Cc: Andy Gross 
Cc: David Brown 
Cc: "Andreas Färber" 
Cc: Kevin Cernekee 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Barry Song 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: "David S. Miller" 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Tony Prisk 
Cc: Michal Simek 
Cc: "Sören Brinkmann" 
Cc: Thomas Gleixner 
Cc: Kate Stewart 
Cc: Philippe Ombredanne 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

tty/serial: altera_uart: Convert timers to use timer_setup()

2017-11-04T11:01:54+00:00

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Tobias Klauser 
Cc: Jiri Slaby 
Cc: linux-serial@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: Kees Cook 
Acked-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

serial: altera_uart: call iounmap() at driver remove

2017-05-25T12:36:37+00:00

The driver calls ioremap() in the probe function but doesn't call
iounmap() in the remove function correspondingly. Do so now.

Follow commit 5c9d6abed9e0 ("serial: altera_jtaguart: adding iounmap()")

Cc: Alexey Khoroshilov 
Signed-off-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman