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2018-02-28serial: sh-sci: prevent lockup on full TTY buffersUlrich Hecht
When the TTY buffers fill up to the configured maximum, a system lockup occurs: [ 598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 598.825796] 0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1 [ 598.832577] (detected by 3, t=62517 jiffies, g=296, c=295, q=126) [ 598.838755] Task dump for CPU 0: [ 598.841977] swapper/0 R running task 0 0 0 0x00000022 [ 598.849023] Call trace: [ 598.851476] __switch_to+0x98/0xb0 [ 598.854870] (null) This can be prevented by doing a dummy read of the RX data register. This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0; reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms as well. Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable <stable@vger.kernel.org> Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250_pci: Add Brainboxes UC-260 4 port serial deviceNikola Ciprich
Add PCI ids for two variants of Brainboxes UC-260 quad port PCI serial cards. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28earlycon: add reg-offset to physical address before mappingGreentime Hu
It will get the wrong virtual address because port->mapbase is not added the correct reg-offset yet. We have to update it before earlycon_map() is called Signed-off-by: Greentime Hu <greentime@andestech.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: stable@vger.kernel.org Fixes: 088da2a17619 ("of: earlycon: Initialize port fields from DT properties") Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: core: mark port as initialized in autoconfigSebastian Andrzej Siewior
This is a followup on 44117a1d1732 ("serial: core: mark port as initialized after successful IRQ change"). Nikola has been using autoconfig via setserial and reported a crash similar to what I fixed in the earlier mentioned commit. Here I do the same fixup for the autoconfig. I wasn't sure that this is the right approach. Nikola confirmed that it fixes his crash. Fixes: b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open") Link: http://lkml.kernel.org/r/20180131072000.GD1853@localhost.localdomain Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Acked-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28serial: 8250_pci: Don't fail on multiport card classAndy Shevchenko
Do not fail on multiport cards in serial_pci_is_class_communication(). It restores behaviour for SUNIX multiport cards, that enumerated by class and have a custom board data. Moreover it allows users to reenumerate port-by-port from user space. Fixes: 7d8905d06405 ("serial: 8250_pci: Enable device after we check black list") Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28tty/serial: atmel: add new version check for usartJonas Danielsson
On our at91sam9260 based board the usart0 and usart1 ports report their versions (ATMEL_US_VERSION) as 0x10302. This version is not included in the current checks in the driver. Signed-off-by: Jonas Danielsson <jonas@orbital-systems.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-09Merge tag 'acpi-part2-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups, a few new quirks, a couple of updates related to the handling of ACPI tables and ACPICA copyrights refreshment. Specifics: - Update the ACPICA kernel code to upstream revision 20180105 including: * Assorted fixes (Jung-uk Kim) * Support for X32 ABI compilation (Anuj Mittal) * Update of ACPICA copyrights to 2018 (Bob Moore) - Prepare for future modifications to avoid executing the _STA control method too early (Hans de Goede) - Make the processor performance control library code ignore _PPC notifications if they cannot be handled and fix up the C1 idle state definition when it is used as a fallback state (Chen Yu, Yazen Ghannam) - Make it possible to use the SPCR table on x86 and to replace the original IORT table with a new one from initrd (Prarit Bhargava, Shunyong Yang) - Add battery-related quirks for Asus UX360UA and UX410UAK and add quirks for table parsing on Dell XPS 9570 and Precision M5530 (Kai Heng Feng) - Address static checker warnings in the CPPC code (Gustavo Silva) - Avoid printing a raw pointer to the kernel log in the smart battery driver (Greg Kroah-Hartman)" * tag 'acpi-part2-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: sbshc: remove raw pointer from printk() message ACPI: SPCR: Make SPCR available to x86 ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit ACPI / tables: Add IORT to injectable table list ACPI / bus: Parse tables as term_list for Dell XPS 9570 and Precision M5530 ACPICA: Update version to 20180105 ACPICA: All acpica: Update copyrights to 2018 ACPI / processor: Set default C1 idle state description ACPI / battery: Add quirk for Asus UX360UA and UX410UAK ACPI: processor_perflib: Do not send _PPC change notification if not ready ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs ACPI / bus: Do not call _STA on battery devices with unmet dependencies PCI: acpiphp_ibm: prepare for acpi_get_object_info() no longer returning status ACPI: export acpi_bus_get_status_handle() ACPICA: Add a missing pair of parentheses ACPICA: Prefer ACPI_TO_POINTER() over ACPI_ADD_PTR() ACPICA: Avoid NULL pointer arithmetic ACPICA: Linux: add support for X32 ABI compilation ACPI / video: Use true for boolean value
2018-02-07ACPI: SPCR: Make SPCR available to x86Prarit Bhargava
SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup an early console. General fixes include updating Documentation & Kconfig (for x86), updating comments, and changing parse_spcr() to acpi_parse_spcr(), and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be more descriptive. On x86, many systems have a valid SPCR table but the table version is not 2 so the table version check must be a warning. On ARM64 when the kernel parameter earlycon is used both the early console and console are enabled. On x86, only the earlycon should be enabled by by default. Modify acpi_parse_spcr() to allow options for initializing the early console and console separately. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-01Merge tag 'driver-core-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of "big" driver core patches for 4.16-rc1. The majority of the work here is in the firmware subsystem, with reworks to try to attempt to make the code easier to handle in the long run, but no functional change. There's also some tree-wide sysfs attribute fixups with lots of acks from the various subsystem maintainers, as well as a handful of other normal fixes and changes. And finally, some license cleanups for the driver core and sysfs code. All have been in linux-next for a while with no reported issues" * tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits) device property: Define type of PROPERTY_ENRTY_*() macros device property: Reuse property_entry_free_data() device property: Move property_entry_free_data() upper firmware: Fix up docs referring to FIRMWARE_IN_KERNEL firmware: Drop FIRMWARE_IN_KERNEL Kconfig option USB: serial: keyspan: Drop firmware Kconfig options sysfs: remove DEBUG defines sysfs: use SPDX identifiers drivers: base: add coredump driver ops sysfs: add attribute specification for /sysfs/devices/.../coredump test_firmware: fix missing unlock on error in config_num_requests_store() test_firmware: make local symbol test_fw_config static sysfs: turn WARN() into pr_warn() firmware: Fix a typo in fallback-mechanisms.rst treewide: Use DEVICE_ATTR_WO treewide: Use DEVICE_ATTR_RO treewide: Use DEVICE_ATTR_RW sysfs.h: Use octal permissions component: add debugfs support bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate ...
2018-01-25tty: serial: exar: Relocate sleep wake-up handlingAaron Sierra
Exar sleep wake-up handling has been done on a per-channel basis by virtue of INT0 being accessible from each channel's address space. I believe this was initially done out of necessity, but now that Exar devices have their own driver, we can do things more efficiently by registering a dedicated INT0 handler at the PCI device level. I see this change providing the following benefits: 1. If more than one port is active, eliminates the redundant bus cycles for reading INT0 on every interrupt. 2. This note associated with hooking in the per-channel handler in 8250_port.c is resolved: /* Fixme: probably not the best place for this */ Cc: Matt Schulte <matts@commtech-fastcom.com> Signed-off-by: Aaron Sierra <asierra@xes-inc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22serial: imx: fix endless loop during suspendMartin Kaiser
Before we go into suspend mode, we enable the imx uart's interrupt for the awake bit in the UART Status Register 1. If, for some reason, the awake bit is already set before we enter suspend mode, we get an interrupt immediately when we enable interrupts for awake. The uart's clk_ipg is disabled at this point (unless there's an ongoing transfer). We end up in the interrupt handler, which usually tries to clear the awake bit. This doesn't work with the clock disabled. Therefore, we keep getting interrupts forever, resulting in an endless loop. Clear the awake bit before setting the awaken bit to signal that we want an imx interrupt when the awake bit will be set. This ensures that we're not woken up by events that happened before we started going into suspend mode. Change the clock handling so that suspend prepares and enables the clock and suspend_noirq disables it. Revert these operations in resume_noirq and resume. With these preparations in place, we can now modify awake and awaken in the suspend function when the actual imx interrupt is disabled and the required clk_ipg is active. Update the thaw and freeze functions to use the new clock handling since we share the suspend_noirq function between suspend and hibernate. Signed-off-by: Martin Kaiser <martin@kaiser.cx> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22serial: core: mark port as initialized after successful IRQ changeSebastian Andrzej Siewior
setserial changes the IRQ via uart_set_info(). It invokes uart_shutdown() which free the current used IRQ and clear TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke uart_startup() before returning to the caller leaving TTY_PORT_INITIALIZED cleared. The next open will crash with | list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98. since the close from the IOCTL won't free the IRQ (and clean the list) due to the TTY_PORT_INITIALIZED check in uart_shutdown(). There is same pattern in uart_do_autoconfig() and I *think* it also needs to set TTY_PORT_INITIALIZED there. Is there a reason why uart_startup() does not set the flag by itself after the IRQ has been acquired (since it is cleared in uart_shutdown)? Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22serial: mxs-auart: don't use GPIOF_* with gpiod_get_directionWolfram Sang
The documentation was wrong, gpiod_get_direction() returns 0/1 instead of the GPIOF_* flags. The docs were fixed with commit 94fc73094abe47 ("gpio: correct docs about return value of gpiod_get_direction"). Now, fix this user (until a better, system-wide solution is in place). This also means we can drop the deprecated use of 'linux/gpio.h'. Yay! Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-22serial: 8250_dw: Revert "Improve clock rate setting"Andy Shevchenko
The commit de9e33bdfa22 ("serial: 8250_dw: Improve clock rate setting") obviously tries to cure symptoms, and not a root cause. The root cause is the non-flexible rate calculation inside the corresponding clock driver. What we need is to provide maximum UART divisor value to the clock driver to allow it do the job transparently to the caller. Since from the initial commit message I have got no clue which clock driver actually needs to be amended, I leave this exercise to the people who know better the case. Moreover, it seems [1] the fix introduced a regression. And possible even one more [2]. Taking above, revert the commit de9e33bdfa22 for now. [1]: https://www.spinics.net/lists/linux-serial/msg28872.html [2]: https://github.com/Dunedan/mbp-2016-linux/issues/29#issuecomment-357583782 Fixes: de9e33bdfa22 ("serial: 8250_dw: Improve clock rate setting") Cc: stable <stable@vger.kernel.org> # 4.15 Cc: Ed Blake <ed.blake@sondrel.com> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09gpio: serial: max310x: Support open-drain configuration for GPIOsJan Kundrát
The push-pull vs. open-drain are the only supported output modes. The inputs are always unconditionally equipped with weak pull-downs. That's the only mode, so there's probably no point in exporting that. I wonder if it's worthwhile to provide a custom dbg_show method to indicate the current status of the outputs, though. This patch and [1] for i2c-gpio together make it possible to bit-bang an I2C bus over GPIOs of an UART which is connected via SPI :). Yes, this is crazy, but it's fast enough (while on a 26Mhz SPI HW bus with a dual-core 1.6GHz CPU) to drive an I2C bus at 200kHz, according to my scope. [1] https://patchwork.ozlabs.org/patch/852591/ Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: 8250_ingenic: Parse earlycon optionsPaul Cercueil
In the devicetree, it is possible to specify the baudrate, parity, bits, flow of the early console, by passing a configuration string like this: aliases { serial0 = &uart0; }; chosen { stdout-path = "serial0:57600n8"; }; This, for instance, will configure the early console for a baudrate of 57600 bps, no parity, and 8 bits per baud. This patches implements parsing of this configuration string in the 8250_ingenic driver, which previously just ignored it. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: 8250_ingenic: Add support for the JZ4770 SoCPaul Cercueil
The JZ4770 SoC's UART is no different from the other JZ SoCs, so this commit simply adds the ingenic,jz4770-uart compatible string. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: core: Make uart_parse_options take const char* argumentPaul Cercueil
The pointed string is never modified from within uart_parse_options, so it should be marked as const in the function prototype. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: 8250_of: fix return code when probe function fails to get resetMasahiro Yamada
The error pointer from devm_reset_control_get_optional_shared() is not propagated. One of the most common problem scenarios is it returns -EPROBE_DEFER when the reset controller has not probed yet. In this case, the probe of the reset consumer should be deferred. Fixes: e2860e1f62f2 ("serial: 8250_of: Add reset support") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTSFabio Estevam
The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS lines, so only allow such wakeup method when the system actually has RTS/CTS support. Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD") Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Acked-by: Fugang Duan <fugang.duan@nxp.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09serial: 8250_uniphier: fix error return code in uniphier_uart_probe()Wei Yongjun
Fix to return a negative error code from the port register error handling case instead of 0, as done elsewhere in this function. Fixes: 39be40ce066d ("serial: 8250_uniphier: fix serial port index in private data") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09tty: omap-serial: Fix initial on-boot RTS GPIO levelRafael Gago
The rs485 flag "SER_RS485_RTS_AFTER_SEND" was wrongly read from the GPIO flags. This caused the RTS pin to be high during boot. Signed-off-by: Rafael Gago Castano <rgc@hms.se> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09tty: serial: jsm: Add one check against NULL pointer dereferenceGuilherme G. Piccoli
All calls to neo_copy_data_from_uart_to_queue() are safeguarded against NULL dereference of its parameter, except the one that this patch changes. That said, let's play safe and check for NULL in this case too. Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09tty: serial: jsm: Remove unnecessary NULL checksGuilherme G. Piccoli
After inspection made by Markus using Coccinelle software, he observed that we could possibly be triggering a NULL pointer dereference in 2 functions [0]. After discussion in mailing list, it was observed in fact we have two unnecessary checks for NULL pointer, and they were leading to Coccinelle warn. So, instead of reworking the code as proposed by him, we hereby remove the unnecessary checks, and also some unneeded extra lines in the code. These two unnecessary NULL checks were tracked in the call chain as never NULL, so they can be safely removed. No functional changes are intended. [0] https://lkml.org/lkml/2017/11/29/705 Suggested-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09treewide: Use DEVICE_ATTR_RWJoe Perches
Convert DEVICE_ATTR uses to DEVICE_ATTR_RW where possible. Done with perl script: $ git grep -w --name-only DEVICE_ATTR | \ xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(\s*S_IRUGO\s*\|\s*S_IWUSR|\s*S_IWUSR\s*\|\s*S_IRUGO\s*|\s*0644\s*)\)?\s*,\s*\1_show\s*,\s*\1_store\s*\)/DEVICE_ATTR_RW(\1)/g; print;}' Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19serial: max310x: Reduce RX work starvationJan Kundrát
Prior to this patch, the code would happily trigger TX on some ports before having a chance of reading the RX buffer from the rest of them. When no flow control was used, this led to RX buffer overruns and therefore lost data under certain circumstances. I was able to reproduce this with MAX14830 (that's a quad channel one) and a simple daisy-chain of RX and TX ports on the eval board: - TX0 -> RX1 - TX1 -> RX2 - TX2 -> RX3 - TX3 -> RX0 I was testing this by transferring 2MB of data at 115200 baud via each port. I used a Solidrun Clearfog Base (Armada 388) which was talking to the UART over an SPI bus clocked at 26MHz (the chip's maximum). Without this patch, I would always get a "Possible RX FIFO overrun" in dmesg, and fewer-than-expected amount of bytes received over ttyMAX0. Results on ttyMAX{1,2,3} tended to be correct all the time, even without the previous patches in this series and with PIO SPI transfers ("indirect mode" as the Marvell datasheet calls it), so I assume that heavy congestion is needed in order to reproduce this. A drawback of this patch is that the throughput gets reduced "a bit". Previously, a 115200 baud resulted in about 11.2kBps throughput as reported by a simple `pv`. With this patch, the throughput of four parallel streams is roughly 7kBps each, and 9kBps for three streams. There is no slowdown for one or two parallel streams. Situation is worse if bytes are being read one-by-one (such as if the userspace wants to perform parity/framing/break checking) and therefore without the batched reads. With just this patch and no other modifications on top of 4.14, I was only getting roughly 3.6kBps with four parallel streams. The single-stream performance was the same, and I was seeing about 7.2kBps with two parallel streams. `perf top` said that a substantial amount of time was spent in `finish_task_switch`, `_raw_spin_unlock_irqrestore` and `__timer_delay`. Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19serial: max310x: Use batched reads when reasonably safeJan Kundrát
The hardware has a 128 byte RX FIFO buffer for each independent UART. Previously, the code was always reading that byte-by-byte via independent SPI transactions and the associated overhead. In practice, this led to up to eight bytes over SPI for just one byte in the UART's RX FIFO: - reading the global IRQ register (two bytes, one for command, the other for data) - reading one UART's ISR (again two bytes) - reading the byte count (two bytes yet again) - finally, reading one byte of the FIFO via another two-byte transaction We cannot always use a batched read. If the TTY is set to intercept break conditions or report framing or parity errors, then it is required to check the Line Status Register (LSR) for each byte which is read from the RX FIFO. The documentation does not show a way of doing that in a single SPI transaction; registers 0x00 and 0x04 are separate. In my testing, this is no silver bullet. I was feeding 2MB of random data over four daisy-chaned UARTs of MAX14830, and this is the distribution that I was getting: - R <= 1: 7437322 - R <= 2: 162093 - R <= 4: 4093 - R <= 8: 4196 - R <= 16: 645 - R <= 32: 165 - R <= 64: 58 - R <= 128: 0 For a reference, batching the write operations works much better: - W <= 1: 2664 - W <= 2: 1305 - W <= 4: 627 - W <= 8: 371 - W <= 16: 121 - W <= 32: 68 - W <= 64: 33 - W <= 128: 63139 That's probably because this HW/SW combination (Clearfog Base, Armada 388) is probably "good enough" to react to the chip's IRQ "fast enough" most of the time. Still, I was getting RX overruns every now and then. In future, I plan to improve this by letting the RX FIFO be filled a little more (the chip has support for that and also for a "stale timeout" to prevent additional starvation). Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19serial: max310x: use a batch write op for UART transmitJan Kundrát
The transmit register supports batched writes. The key is simply to keep sending additional bytes up to the FIFO size in the same SPI transaction with the CS pin still being held low. This duplicates the regmap infrastructure to a certain extent. There are some provisions for multiple writes in there, but there does not appear to be any support for those writes which are destined to the *same* register (and also no standard for SPI bus transfers of these, anyway). This patch does not solve every case (if the UART xmit circular buffer wraps around, we're still doing two SPI transactions), but at least it's not one-byte-per-transaction anymore. This change does not touch the receive path at this time. Doing that in the generic case appears to be impossible in the general case, because the chips' status register contains data about the *current* byte in the HW's Rx FIFO. We cannot read these two registers in one go, unfortunately. Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19serial: max310x: Support IRQ sharing with other devicesJan Kundrát
According to my chip's datasheet [1], the IRQ output is an open collector pin which is suitable for sharing with other chips. The chip also has a register which indicates which UART performed a change and the driver checks that register already, so we have everything what is needed to effectively share the IRQ GPIO. [1] https://datasheets.maximintegrated.com/en/ds/MAX14830.pdf Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19serial: max310x: Do not hard-code the IRQ typeJan Kundrát
As suggested by Russell King, a driver should not really care about bits such as the interrupt polarity or whether it is edge- or level- triggered. The reasons for that include: - an upstream IRQ controller which cannot support edge- or level-triggered interrupts, - board design with a built-in inverter The interrupt type is being already specified by the Device Tree, anyway. Other drivers (gpio/gpio-tc3589x.c for example) already work in this way, delegating the proper IRQ line setup to the DT and not specifying anything by hand. Also, there's no reason to have the IRQ flags split between two places. The SPI probing is the only entry point anyway. Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18tty: serial: sh-sci: Add default for number of ports for compile-testingGeert Uytterhoeven
When compile-testing an allmodconfig kernel for a platform without sh-sci serial ports, the SERIAL_SH_SCI_NR_UARTS symbol of type "int" doesn't get assigned a numerical default value, but an empty string, leading to a build failure: .config:3814:warning: symbol value '' invalid for SERIAL_SH_SCI_NR_UARTS ... make[3]: *** [silentoldconfig] Error 1 Fix this by explicitly providing a default value of 2, like before. Reported-by: kbuild test robot <fengguang.wu@intel.com> Fixes: f6731485a51978ca ("tty: serial: sh-sci: Hide number of ports config question") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15serial: max310x: Fix invalid memory access during GPIO initJan Kundrát
The `max310x_spi_probe` function attempted to setup the GPIO bits before the corresponding structs for each serial port were initialized. If the DTS file specified a GPIO hog, this led to a crash because the GPIO stack ended up calling `max310x_gpio_direction_output` which referenced uninitialized memory: [<c04598c0>] (max310x_gpio_direction_output) from [<c03f5a2c>] (_gpiod_direction_output_raw+0x94/0x2d4) [<c03f5a2c>] (_gpiod_direction_output_raw) from [<c03f991c>] (gpiod_hog+0x6c/0x154) [<c03f991c>] (gpiod_hog) from [<c03fa2d8>] (of_gpiochip_add+0x28c/0x444) [<c03fa2d8>] (of_gpiochip_add) from [<c03f6b2c>] (gpiochip_add_data+0x4f8/0x760) [<c03f6b2c>] (gpiochip_add_data) from [<c03f6dd4>] (devm_gpiochip_add_data+0x40/0x7c) [<c03f6dd4>] (devm_gpiochip_add_data) from [<c0459fec>] (max310x_spi_probe+0x530/0x894) [<c0459fec>] (max310x_spi_probe) from [<c0503294>] (spi_drv_probe+0x7c/0xac) [<c0503294>] (spi_drv_probe) from [<c046628c>] (driver_probe_device+0x234/0x2e8) [<c046628c>] (driver_probe_device) from [<c0464890>] (bus_for_each_drv+0x60/0x94) [<c0464890>] (bus_for_each_drv) from [<c0465f78>] (__device_attach+0xb0/0x114) [<c0465f78>] (__device_attach) from [<c0465548>] (bus_probe_device+0x84/0x8c) [<c0465548>] (bus_probe_device) from [<c0463a00>] (device_add+0x3f4/0x580) [<c0463a00>] (device_add) from [<c0504164>] (spi_add_device+0x9c/0x134) [<c0504164>] (spi_add_device) from [<c0504c18>] (spi_register_controller+0x484/0x910) [<c0504c18>] (spi_register_controller) from [<c0506ee0>] (orion_spi_probe+0x2f4/0x3b4) [<c0506ee0>] (orion_spi_probe) from [<c0467dac>] (platform_drv_probe+0x50/0xb0) [<c0467dac>] (platform_drv_probe) from [<c046628c>] (driver_probe_device+0x234/0x2e8) [<c046628c>] (driver_probe_device) from [<c04663f8>] (__driver_attach+0xb8/0xbc) [<c04663f8>] (__driver_attach) from [<c04647e8>] (bus_for_each_dev+0x68/0x9c) [<c04647e8>] (bus_for_each_dev) from [<c046574c>] (bus_add_driver+0x104/0x210) [<c046574c>] (bus_add_driver) from [<c0466f14>] (driver_register+0x78/0xf4) [<c0466f14>] (driver_register) from [<c0101bdc>] (do_one_initcall+0x44/0x168) [<c0101bdc>] (do_one_initcall) from [<c0a00dc0>] (kernel_init_freeable+0x140/0x1cc) [<c0a00dc0>] (kernel_init_freeable) from [<c078c590>] (kernel_init+0x8/0x108) [<c078c590>] (kernel_init) from [<c0107a50>] (ret_from_fork+0x14/0x24) This can be easily fixed by moving the corresponding code below. And because the UARTs are already there by the time we reach this point, the `goto` needs changing so that more stuff is freed. (I have not tested this error path.) Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15tty: serial: mxs-auart: fix error handling in mxs_auart_probeBranislav Radocaj
If uart_add_one_port() fails in mxs_auart_probe, the clks has to be disabled.Two clks are previously enabled in mxs_get_clks(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Branislav Radocaj <branislav@radocaj.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15serial: 8250: 8250_omap: Fix spelling error.Rolf Evers-Fischer
Fixed a spelling error in a comment. Signed-off-by: Rolf Evers-Fischer <rolf.evers.fischer@aptiv.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15serial: 8250_dw: Disable clock on errorStefan Potyra
If there is no clock rate for uartclk defined, disable the previously enabled clock again. Found by Linux Driver Verification project (linuxtesting.org). Fixes: 23f5b3fdd04e serial: 8250_dw: only get the clock rate in one place Signed-off-by: Stefan Potyra <Stefan.Potyra@elektrobit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15serial: stm32: fix name conflict with 8250Ludovic Barre
This patch replaces stm32 tty name ttyS by ttySTM to avoid a name conflict when Serial: 8250/16550 driver is activated. sysfs: cannot create duplicate filename '/class/tty/ttyS3' Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-12903-gb392521-dirty #1 [<c03118dc>] (unwind_backtrace) from [<c030c950>] (show_stack+0x10/0x14) [<c030c950>] (show_stack) from [<c0d31e18>] (dump_stack+0x90/0xa4) [<c0d31e18>] (dump_stack) from [<c03430a0>] (__warn+0xf8/0x110) [<c03430a0>] (__warn) from [<c03430f0>] (warn_slowpath_fmt+0x38/0x48) [<c03430f0>] (warn_slowpath_fmt) from [<c04ce574>] (sysfs_warn_dup+0x68/0x78) [<c04ce574>] (sysfs_warn_dup) from [<c04ce824>] (sysfs_do_create_link_sd+0xb4/0xc4) [<c04ce824>] (sysfs_do_create_link_sd) from [<c08c60ec>] (device_add+0x204/0x574) [<c08c60ec>] (device_add) from [<c07a7ddc>] (tty_register_device_attr+0xc8/0x1bc) [<c07a7ddc>] (tty_register_device_attr) from [<c07c6530>] (uart_add_one_port+0x22c/0x4f4) Signed-off-by: Ludovic Barre <ludovic.barre@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15tty: serial: sh-sci: Hide DMA config questionGeert Uytterhoeven
On most Renesas ARM platforms, the SCIF serial ports can be used with DMA, so most users will want DMA support to be enabled. On SuperH platforms, SCI(F) serial ports cannot be used with DMA yet (see also commit 219fb0c1436e4893 ("serial: sh-sci: Remove the platform data dma slave rx/tx channel IDs")), so users will want it disabled to reduce kernel size. Hence follow the above rationale to configure the default, unless CONFIG_EXPERT is enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15tty: serial: sh-sci: Hide earlycon config questionGeert Uytterhoeven
Renesas H8/300 and ARM platforms use DT and support earlycon, so most users want earlycon support to be enabled. On SuperH platforms, earlycon is not yet supported. Hence follow the above rationale to configure the default, unless CONFIG_EXPERT is enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15tty: serial: sh-sci: Hide serial console config questionGeert Uytterhoeven
Most users will want to use a serial console. Hence make that the default, unless CONFIG_EXPERT is enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15tty: serial: sh-sci: Hide number of ports config questionGeert Uytterhoeven
Auto-configure the maximum number of serial ports based on how many can be present on the architecture: - 3 on H8/300, - 10 on SuperH, - 18 on Reneas ARM. The default can still be overridden if CONFIG_EXPERT is enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-15serial: forbid 8250 on s390Christian Borntraeger
Using "make kvmconfig" results in a potentially unusable linux image on s390. The reason is that both the (default on s390) sclp consoles as well as the 8250 console register a ttyS<x> as console. Since there will be no 8250 on s390 let's fence 8250. This will ensure that there is always a working sclp console. Reported-by: Alice Frosi <alice@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-11Merge 4.15-rc3 into tty-nextGreg Kroah-Hartman
We want the serial/tty fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: imx: Support common rs485 binding for RTS polarityLukas Wunner
Invoke the ->rs485_config callback on probe to adjust the initial RTS polarity based on the UART's device properties. This implicitly fixes a bug: If RTS control is not available, rs485 should be disabled even if it was enabled through a device property. Log an error when that occurs. Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: fsl_lpuart: Support common rs485 binding for RTS polarityLukas Wunner
Invoke the ->rs485_config callback on probe to set UARTMODEM_TXRTSPOL appropriately based on the UART's device properties. This implicitly sets UARTMODEM_TXRTSE if rs485 was enabled in the device properties, so drop the identical code from lpuart_probe(). It also fixes a bug: If an unsupported rs485 property was specified (rs485-rx-during-tx or rs485-rts-delay), the driver returns -ENOSYS without performing any cleanup, in particular without calling uart_remove_one_port() or clk_disable_unprepare(), thus leaking the uart_port. But with the invocation of ->rs485_config, the unsupported properties are now cleared in struct serial_rs485 and thus ignored. It therefore seems sufficient to just log an error instead of bailing out. Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: core: Support common rs485 binding for RTS polarityLukas Wunner
When a driver invokes the uart_get_rs485_mode() helper, set the RTS polarity to active high by default unless the newly introduced "rs485-rts-active-low" property was specified. imx contains a line to set the default RTS polarity to active high, it is now superfluous and hence deleted. omap-serial historically defaults to active low and supports an "rs485-rts-active-high" property to inverse the polarity. Retain that behavior for compatibility. Cc: Mark Jackson <mpfj@newflow.co.uk> Cc: Michał Oleszczyk <oleszczyk.m@gmail.com> Cc: Rafael Gago Castano <rgc@hms.se> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: Make retrieval of rs485 properties platform-agnosticLukas Wunner
Commit ef838a81dd4d ("serial: Add common rs485 device tree parsing function") consolidated retrieval of rs485 OF properties in a common helper function but did not #ifdef it to CONFIG_OF. The function is therefore included on ACPI platforms as well even though it's not used. On the other hand ACPI platforms with rs485 do exist (e.g. Siemens IOT2040) and they may leverage _DSD to store rs485 properties. Likewise, UART platform devices instantiated from an MFD should be able to specify rs485 properties. In fact, the tty subsystem maintainer had asked for a "generic" function during review of commit ef838a81dd4d: https://marc.info/?l=linux-serial&m=150143441725194&w=4 Thus, instead of constraining the helper to OF platforms, make it platform-agnostic by converting it to device_property_*() functions and renaming it accordingly. In imx.c, move the invocation of uart_get_rs485_mode() from serial_imx_probe_dt() to serial_imx_probe() so that it also gets called for non-OF devices. In omap-serial.c, move its invocation further up within serial_omap_probe_rs485() so that the RTS polarity can be overridden with the driver-specific "rs485-rts-active-high" property once we introduce a generic "rs485-rts-active-low" property. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: 8250_early: Only set divisor if valid clk & baudMatt Redfearn
If either uartclk or baud are 0, avoid calculating and setting a divisor based on them since the output will almost certainly be garbage. This also allows platforms such as the MIPS generic kernel, which has no way to know a valid BASE_BASE for the board it is actually booted on at compile time, to set BASE_BAUD to 0 and avoid early_8250 setting a bad divisor. This fixes a regression caused by commit 31cb9a8575ca ("earlycon: initialise baud field of earlycon device structure"), which changed the behavior of of_setup_earlycon such that it sets a baud rate in the earlycon structure where previously it was left as 0. All boards supported by the MIPS generic kernel started outputting garbage from the boot console due to an incorrect divisor being set. Fixes: 31cb9a8575ca ("earlycon: initialise baud field of earlycon device structure") Cc: stable <stable@vger.kernel.org> # 4.14 Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: 8250_pci: Add Amazon PCI serial device IDMatt Wilson
This device will be used in future Amazon EC2 instances as the primary serial port (i.e., data sent to this port will be available via the GetConsoleOuput [1] EC2 API). [1] http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetConsoleOutput.html Cc: stable <stable@vger.kernel.org> Signed-off-by: Matt Wilson <msw@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28tty: serial: imx: remove imx_disable_rx_intTroy Kisky
Since imx_disable_rx_int is only called by imx_startup, let's integrate it into that function. Notice UCR2_ATEN is never set by the driver. The bit is still cleaned to make this patch a noop. Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28serial: pl011: Use cached copy of IMSC registerLukas Wunner
Commit 075167ed71b7 ("drivers: PL011: replace UART_MIS reading with _RIS & _IMSC") amended this driver's interrupt handler to read the Raw Interrupt Status (RIS) and Interrupt Mask Set/Clear (IMSC) registers instead of the Masked Interrupt Status (MIS) register. The change was made to attain compatibility with SBSA UARTs which lack the MIS register. However the IMSC register is cached by the driver. Using the cached copy saves one register read per interrupt. I've tested this change successfully on a BCM2837 (Raspberry Pi CM3). Cc: Mathias Duckeck <m.duckeck@kunbus.de> Cc: Phil Elwell <phil@raspberrypi.org> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Mark Langsdorf <mlangsdo@redhat.com> Cc: Naresh Bhat <nbhat@cavium.com> Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>