When using the geni-serial as console, its important to be
able to hit the lowest possible power state in suspend,
even with no_console_suspend.
The only thing that prevents it today on platforms like the sc7180
is the interconnect BW votes, which we certainly don't need when
the system is in suspend. So in the suspend handler mark them as
ACTIVE_ONLY (0x3) and on resume switch them back to the ALWAYS tag (0x7)
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1594704709-26072-1-git-send-email-rnayak@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
The geni serial driver had the rather sketchy hack in it where it
would adjust the number of bytes per RX FIFO word from 4 down to 1 if
it detected that CONFIG_CONSOLE_POLL was enabled (for kgdb) and this
was a console port (defined by the kernel directing output to this
port via the "console=" command line argument).
The problem with that sketchy hack is that it's possible to run kgdb
over a serial port even if it isn't used for console.
Let's avoid the hack by simply handling the 4-bytes-per-FIFO word case
for kdb. We'll have to have a (very small) cache but that should be
fine.
A nice side effect of this patch is that an agetty (or similar)
running on this port is less likely to drop characters. We'll
have roughly 4 times the RX FIFO depth than we used to now.
NOTE: the character cache here isn't shared between the polling API
and the non-polling API. That means that, technically, the polling
API could eat a few extra bytes. This doesn't seem to pose a huge
problem in reality because we'll only get several characters per FIFO
word if those characters are all received at nearly the same time and
we don't really expect non-kgdb characters to be sent to the same port
as kgdb at the exact same time we're exiting kgdb.
ALSO NOTE: we still have the sketchy hack for setting the number of
bytes per TX FIFO word in place, but that one is less bad. kgdb
doesn't have any problem with this because it always just sends 1 byte
at a time and waits for it to finish. The TX FIFO hack is only really
needed for console output. In any case, a future patch will remove
that hack, too.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200626125844.1.I8546ecb6c5beb054f70c5302d1a7293484212cd1@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
The comment near to uart_port_spin_lock_init() says:
Ensure that the serial console lock is initialised early.
If this port is a console, then the spinlock is already initialised.
and there is nothing about enabled or disabled consoles. The commit
a3cb39d258 ("serial: core: Allow detach and attach serial device
for console") made a change, which follows the comment, and also to
prevent reinitialisation of the lock in use, when user detaches and
attaches back the same console device. But this change discovers
another issue, that uart_add_one_port() tries to access a spin lock
that now may be uninitialised. This happens when a driver expects
the serial core to register a console on its behalf. In this case
we must initialise a spin lock before use.
Fixes: a3cb39d258 ("serial: core: Allow detach and attach serial device for console")
Reported-by: Marc Zyngier <maz@kernel.org>
Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20200706214903.56148-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 8e20fc3917 ("serial_core: Move sysrq functions from header
file") converted the inline sysrq helpers to exported functions which
are now called for every received character, interrupt and break signal
also on systems without CONFIG_MAGIC_SYSRQ_SERIAL instead of being
optimised away by the compiler.
Inlining these helpers again also avoids the function call overhead when
CONFIG_MAGIC_SYSRQ_SERIAL is enabled (e.g. when the port is not used as
a console).
Fixes: 8e20fc3917 ("serial_core: Move sysrq functions from header file")
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20200610152232.16925-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit a4912303ac ("serial: kgdboc: Allow earlycon initialization
to be deferred") it looks like Daniel really took Linus's new
suggestion about not needing to wrap at 80 columns to heart and he
jammed two full lines of comments into one line. Either that or he
just somehow accidentally deleted a carriage return when doing final
edits on the patch. In either case let's make it look prettier.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200602124044.1.Iee31247bc080d42a02e167454b1225a1b4283705@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since dev_err() calls can lead to synchronous writes to another serial
console these calls can provide significant latency during irq-handling
in tegra_uart_isr(). With this latency another interrupt is likely to
apper during handling of the first interrupt, which might lock up the
kernel completely.
These errors are reported to the error counters so converting the
dev_err() to dev_dbg() is appropriate.
Signed-off-by: Randolph Maaßen <gaireg@gaireg.de>
Link: https://lore.kernel.org/r/20200605145714.9964-1-gaireg@gaireg.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
devm_gpiod_get_index() doesn't return NULL but -ENOENT when the
requested GPIO doesn't exist, leading to the following messages:
[ 2.742468] gpiod_direction_input: invalid GPIO (errorpointer)
[ 2.748147] can't set direction for gpio #2: -2
[ 2.753081] gpiod_direction_input: invalid GPIO (errorpointer)
[ 2.758724] can't set direction for gpio #3: -2
[ 2.763666] gpiod_direction_output: invalid GPIO (errorpointer)
[ 2.769394] can't set direction for gpio #4: -2
[ 2.774341] gpiod_direction_input: invalid GPIO (errorpointer)
[ 2.779981] can't set direction for gpio #5: -2
[ 2.784545] ff000a20.serial: ttyCPM1 at MMIO 0xfff00a20 (irq = 39, base_baud = 8250000) is a CPM UART
Use devm_gpiod_get_index_optional() instead.
At the same time, handle the error case and properly exit
with an error.
Fixes: 97cbaf2c82 ("tty: serial: cpm_uart: Convert to use GPIO descriptors")
Cc: stable@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/694a25fdce548c5ee8b060ef6a4b02746b8f25c0.1591986307.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the code slightly more readable by removing unneeded line breaks,
adding missing line breaks and white spaces. This also fixes few strict
checkpatch suggestions:
CHECK: spaces preferred around that '-' (ctx:VxV)
CHECK: Unbalanced braces around else statement
CHECK: Lines should not end with a '('
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200617152856.18086-1-krzk@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In kgdb context, calling console handlers aren't safe due to locks used
in those handlers which could in turn lead to a deadlock. Although, using
oops_in_progress increases the chance to bypass locks in most console
handlers but it might not be sufficient enough in case a console uses
more locks (VT/TTY is good example).
Currently when a driver provides both polling I/O and a console then kdb
will output using the console. We can increase robustness by using the
currently active polling I/O driver (which should be lockless) instead
of the corresponding console. For several common cases (e.g. an
embedded system with a single serial port that is used both for console
output and debugger I/O) this will result in no console handler being
used.
In order to achieve this we need to reverse the order of preference to
use dbg_io_ops (uses polling I/O mode) over console APIs. So we just
store "struct console" that represents debugger I/O in dbg_io_ops and
while emitting kdb messages, skip console that matches dbg_io_ops
console in order to avoid duplicate messages. After this change,
"is_console" param becomes redundant and hence removed.
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/1591264879-25920-5-git-send-email-sumit.garg@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
QUP core clock is shared among all the SE drivers present on particular
QUP wrapper, the system will reset(unclocked access) if earlycon used after
QUP core clock is put to 0 from other SE drivers before real console comes
up.
As earlycon can't vote for it's QUP core need, to fix this add ICC
support to common/QUP wrapper driver and put vote for QUP core from
probe on behalf of earlycon and remove vote during earlycon exit call.
Signed-off-by: Akash Asthana <akashast@codeaurora.org>
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/1592908737-7068-3-git-send-email-akashast@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.
Effectively no change.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull tty/serial driver updates from Greg KH:
"Here is the tty and serial driver updates for 5.8-rc1
Nothing huge at all, just a lot of little serial driver fixes, updates
for new devices and features, and other small things. Full details are
in the shortlog.
All of these have been in linux-next with no issues for a while"
* tag 'tty-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (67 commits)
tty: serial: qcom_geni_serial: Add 51.2MHz frequency support
tty: serial: imx: clear Ageing Timer Interrupt in handler
serial: 8250_fintek: Add F81966 Support
sc16is7xx: Add flag to activate IrDA mode
dt-bindings: sc16is7xx: Add flag to activate IrDA mode
serial: 8250: Support rs485 bus termination GPIO
serial: 8520_port: Fix function param documentation
dt-bindings: serial: Add binding for rs485 bus termination GPIO
vt: keyboard: avoid signed integer overflow in k_ascii
serial: 8250: Enable 16550A variants by default on non-x86
tty: hvc_console, fix crashes on parallel open/close
serial: imx: Initialize lock for non-registered console
sc16is7xx: Read the LSR register for basic device presence check
sc16is7xx: Allow sharing the IRQ line
sc16is7xx: Use threaded IRQ
sc16is7xx: Always use falling edge IRQ
tty: n_gsm: Fix bogus i++ in gsm_data_kick
tty: n_gsm: Remove unnecessary test in gsm_print_packet()
serial: stm32: add no_console_suspend support
tty: serial: fsl_lpuart: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
...
Pull kgdb updates from Daniel Thompson:
"By far the biggest change in this cycle are the changes that allow
much earlier debug of systems that are hooked up via UART by taking
advantage of the earlycon framework to implement the kgdb I/O hooks
before handing over to the regular polling I/O drivers once they are
available. When discussing Doug's work we also found and fixed an
broken raw_smp_processor_id() sequence in in_dbg_master().
Also included are a collection of much smaller fixes and tweaks: a
couple of tweaks to ged rid of doc gen or coccicheck warnings, future
proof some internal calculations that made implicit power-of-2
assumptions and eliminate some rather weird handling of magic
environment variables in kdb"
* tag 'kgdb-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kdb: Remove the misfeature 'KDBFLAGS'
kdb: Cleanup math with KDB_CMD_HISTORY_COUNT
serial: amba-pl011: Support kgdboc_earlycon
serial: 8250_early: Support kgdboc_earlycon
serial: qcom_geni_serial: Support kgdboc_earlycon
serial: kgdboc: Allow earlycon initialization to be deferred
Documentation: kgdboc: Document new kgdboc_earlycon parameter
kgdb: Don't call the deinit under spinlock
kgdboc: Disable all the early code when kgdboc is a module
kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles
kgdboc: Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc
kgdb: Prevent infinite recursive entries to the debugger
kgdb: Delay "kgdbwait" to dbg_late_init() by default
kgdboc: Use a platform device to handle tty drivers showing up late
Revert "kgdboc: disable the console lock when in kgdb"
kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb
kgdb: Return true in kgdb_nmi_poll_knock()
kgdb: Drop malformed kernel doc comment
kgdb: Fix spurious true from in_dbg_master()
Currently there is no guarantee that an earlycon will be initialized
before kgdboc tries to adopt it. Almost the opposite: on systems
with ACPI then if earlycon has no arguments then it is guaranteed that
earlycon will not be initialized.
This patch mitigates the problem by giving kgdboc_earlycon a second
chance during console_init(). This isn't quite as good as stopping during
early parameter parsing but it is still early in the kernel boot.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200430161741.1832050-1-daniel.thompson@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
When kgdboc is compiled as a module all of the "ekgdboc" and
"kgdb_earlycon" code isn't useful and, in fact, breaks compilation.
This is because early_param() isn't defined for modules and that's how
this code gets configured.
It turns out that this was broken by commit eae3e19ca9 ("kgdboc:
Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc") and then
made worse by commit 220995622d ("kgdboc: Add kgdboc_earlycon to
support early kgdb using boot consoles"). I guess the #ifdef wasn't
so useless, even if it wasn't obvious why it was useful. When kgdboc
was compiled as a module only "CONFIG_KGDB_SERIAL_CONSOLE_MODULE" was
defined, not "CONFIG_KGDB_SERIAL_CONSOLE". That meant that the old
module.
Let's basically do the same thing that the old code (pre-removal of
the #ifdef) did but use "IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)" to
make it more obvious what the point of the check is. We'll fix
kgdboc_earlycon in a similar way.
Fixes: 220995622d ("kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles")
Fixes: eae3e19ca9 ("kgdboc: Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200519084345.1.I91670accc8a5ddabab227eb63bb4ad3e2e9d2b58@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
To support BT use case over UART at baud rate of 3.2 Mbps,
we need SE clocks to run at 51.2MHz frequency. Previously this
frequency was not available in clk src, so, we were requesting
for 102.4 MHz and dividing it internally by 2 to get 51.2MHz.
As now 51.2MHz frequency is made available in clk src,
adding this frequency to UART frequency table.
We will save significant amount of power, if 51.2 is used
because it belongs to LowSVS range whereas 102.4 fall into
Nominal category.
Signed-off-by: satya priya <skakit@codeaurora.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1590747282-5487-1-git-send-email-skakit@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The AGTIM flag must be cleared explicitly, otherwise the IRQ handler
will be called in an endless loop.
Fortunately, this issue currently doesn't affect mainline kernels in
practice, as the the RX FIFO trigger level is set to 1 in UFCR. When
setting the trigger level to a higher number, the issue is trivially
reproducible by any RX without DMA that doesn't fill the FIFO up to the
configured level.
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20200528154747.14201-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e8759ad17d ("serial: uapi: Add support for bus termination")
introduced the ability to enable rs485 bus termination from user space.
So far the feature is only used by a single driver, 8250_exar.c, using a
hardcoded GPIO pin specific to Siemens IOT2040 products.
Provide for a more generic solution by allowing specification of an
rs485 bus termination GPIO pin in the device tree: Amend the serial
core to retrieve the GPIO from the device tree (or ACPI table) and amend
the default ->rs485_config() callback for 8250 drivers to change the
GPIO on request from user space.
Perhaps 8250_exar.c can be converted to the generic approach in a
follow-up patch.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The commit a3cb39d258
("serial: core: Allow detach and attach serial device for console")
changed a bit logic behind lock initialization since for most of the console
driver it's supposed to have lock already initialized even if console is not
enabled. However, it's not the case for Freescale IMX console.
Initialize lock explicitly in the ->probe().
Note, there is still an open question should or shouldn't not this driver
register console properly.
Fixes: a3cb39d258 ("serial: core: Allow detach and attach serial device for console")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200525105952.13744-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
