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2014-05-28serial: sc16is7xx: compile I2C when REGMAP_I2C is moduleJan Moskyto Matejka1-2/+0
drivers/tty/serial/sc16is7xx.c:1060:12: warning: 'sc16is7xx_probe' defined but not used [-Wunused-function] static int sc16is7xx_probe(struct device *dev, ^ drivers/tty/serial/sc16is7xx.c:1176:12: warning: 'sc16is7xx_remove' defined but not used [-Wunused-function] static int sc16is7xx_remove(struct device *dev) ^ drivers/tty/serial/sc16is7xx.c:1215:29: warning: 'regcfg' defined but not used [-Wunused-variable] static struct regmap_config regcfg = { ^ Fixed these warnings by removing the `#ifdef CONFIG_REGMAP_I2C' around their calls as this driver selects REGMAP_I2C in Kconfig. This part of driver just didn't compile at all when REGMAP_I2C configured as module (CONFIG_REGMAP_I2C is not defined, just CONFIG_REGMAP_I2C_MODULE). Signed-off-by: Jan Moskyto Matejka <mq@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27tty: n_hdlc: Drop redundant error messageJean Delvare1-4/+0
On initialization failure, an error message is already printed with level KERN_ERR, no need to print another one with level KERN_INFO. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27serial: pch_uart: Fix Kconfig dependenciesJean Delvare1-1/+1
The pch_uart driver is for a companion chip to the Intel Atom E600 series processors. These are 32-bit x86 processors so the driver is only needed on X86_32. Add COMPILE_TEST as an alternative, so that the driver can still be build-tested elsewhere. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-04tty/serial: fix generic earlycon option parsingRob Herring1-13/+5
Commit 9aac5887595 (tty/serial: add generic serial earlycon) moved console option parsing from 8250_early.c and converted to kstrto* functions from simple_strtoul along the way. However, kstrto* functions are not equivalent in that they do not allow non-convertible characters at the end such as "115200n8". Fix this by changing back to simple_strtoul and ignore what checkpatch.pl says. Reported-by: Yinghai Lu <yinghai@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-04tty/serial: add back missing setup_early_serial8250_consoleRob Herring1-0/+10
Commit d2fd6810a823bcd (tty/serial: convert 8250 to generic earlycon) removed setup_early_serial8250_console, but there are still 2 callers in: arch/mips/mti-malta/malta-init.c drivers/firmware/pcdp.c Add back the function implemented as a wrapper to setup_earlycon. Reported-by: Yinghai Lu <yinghai@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-28Merge 3.15-rc3 into tty-nextGreg Kroah-Hartman5-34/+55
2014-04-26serial: sc16is7xx: fix implicit decl of func copy_{to,from}_userJon Ringle1-0/+1
Fix by including linux/uaccess.h: drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_ioctl': >> drivers/tty/serial/sc16is7xx.c:861:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration] >> drivers/tty/serial/sc16is7xx.c:867:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration] Signed-off-by: Jon Ringle <jringle@gridpoint.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-26serial: sc16is7xx: depend on I2CJon Ringle1-0/+1
Signed-off-by: Jon Ringle <jringle@gridpoint.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: sc16is7xxJon Ringle3-0/+1289
The SC16IS7xx is a slave I2C-bus/SPI interface to a single-channel high performance UART. The SC16IS7xx's internal register set is backward-compatible with the widely used and widely popular 16C450. The SC16IS7xx also provides additional advanced features such as auto hardware and software flow control, automatic RS-485 support, and software reset. Signed-off-by: Jon Ringle <jringle@gridpoint.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25Revert "serial: sh-sci: Add device tree support for r8a7779"Greg Kroah-Hartman1-9/+1
This reverts commit fcbee4d49f30eb0eaa83a62e6a3cab5a892ed93f. It wasn't quite ready to go in yet, sorry about that. Cc: Simon Horman <horms@verge.net.au> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty/serial: add arm/arm64 semihosting earlyconRob Herring3-0/+72
Add earlycon support for the arm/arm64 semihosting debug serial interface. This allows enabling a debug console when early_params are processed. This is based on the arm64 earlyprintk smh support and is intended to replace it. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty/serial: pl011: add generic earlycon supportRob Herring2-1/+30
Add earlycon support for the pl011 serial port. This allows enabling the pl011 for console when early_params are processed. This is based on the arm64 earlyprintk support and is intended to replace it. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty/serial: convert 8250 to generic earlyconRob Herring2-123/+16
With the generic earlycon infrastructure in place, convert the 8250 early console to use it. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty/serial: add generic serial earlyconRob Herring3-0/+161
This introduces generic earlycon infrastructure for serial devices based on the 8250 earlycon. This allows for supporting earlycon option with other serial devices. The earlycon output is enabled at the time early_params are processed. Only architectures that have fixmap support or have functional ioremap when early_params are processed are supported. This is the same restriction that the 8250 driver had. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25x86: move FIX_EARLYCON_MEM kconfig into x86Rob Herring1-5/+0
In preparation to support FIX_EARLYCON_MEM on other arches, make the option per arch. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: Add driver for MEN's 16z135 High Speed UART.Johannes Thumshirn3-0/+877
Add driver for MEN's 16z135 High Speed UART. The 16z135 is a memory mapped UART Core on an MCB FPGA and has 1024 byte deep FIFO buffers for the RX and TX path. It also has configurable FIFO fill level IRQs and data copied to and from the hardware has to be acknowledged. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de> Reviewed-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Rebrand driver as Cadence UARTSoren Brinkmann2-447/+470
Zynq's UART is Cadence IP. Make this visible in the prompt in kconfig and additional comments in the driver. This also renames functions and symbols, as far as possible without breaking user space API, to reflect the Cadence origin. This is achieved through simple search and replace: - s/XUARTPS/CDNS_UART/g - s/xuartps/cdns_uart/g The only exceptions are PORT_XUARTPS and the driver name, which stay as is, due to their exposure to user space. As well as the - no legacy - compatibility string 'xlnx,xuartps' Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Don't write IRQ disable register to enable interruptsSoren Brinkmann1-5/+1
A comment states, that, according to the data sheet, to enable interrupts the disable register should be written, but the enable register could be left untouched. And it suspsects a HW bug requiring to write both. Reviewing the data sheet, these statements seem wrong. Just as one would expect. Writing to the enable/disable register enables/disables interrupts. Hence the misleading comment and needless write to the disable register are removed from the enable sequence. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Refactor read-modify-writesSoren Brinkmann1-28/+24
A lot of read-modify-write sequences used a one-line statement which nests a readl() within a writel(). Convert this into code sequences that make the three steps more obvious. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Print warning in clock notifierSoren Brinkmann1-1/+3
Print a warning if the clock notifier rejects a clock frequency change to facilitate debugging (see: http://thread.gmane.org/gmane.linux.ports.arm.kernel/304329/focus=304379) Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Clean upSoren Brinkmann1-136/+74
This is all white space and comment clean up. Mostly reformatting comments. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Initialize ports according to aliasesMichal Simek1-8/+16
Register port numbers according to order in DT aliases. If aliases are not defined, order in DT is used. If aliases are defined, register port id based on that. This patch ensures proper ttyPS0/1 assignment. [soren]: Combined integer declarations in probe(), removed warning message if no alias is found. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: xuartps: Fix kernel-doc errors in the driverMichal Simek1-60/+49
No functional changes. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: fix Sparse warningsFelipe Balbi1-2/+2
Fix the following Sparse warnings: drivers/tty/serial/omap-serial.c:1418:49: warning: incorrect \ type in argument 2 (different address spaces) drivers/tty/serial/omap-serial.c:1418:49: expected void const \ [noderef] <asn:1>*from drivers/tty/serial/omap-serial.c:1418:49: got struct serial_rs485 \ *<noident> drivers/tty/serial/omap-serial.c:1426:35: warning: incorrect \ type in argument 1 (different address spaces) drivers/tty/serial/omap-serial.c:1426:35: expected void [noderef] \ <asn:1>*to drivers/tty/serial/omap-serial.c:1426:35: got struct serial_rs485 \ *<noident> Reported-by: Nishanth Menon <nm@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: remove unneeded singlethread workqueueFelipe Balbi1-3/+0
it wasn't used by anything, just remove it. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: remove some dead codeFelipe Balbi1-39/+0
nobody passes a DTR_gpio to this driver, so this code is not necessary. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: switch over to devm_ioremap_resourceFelipe Balbi1-23/+9
just using helper function to remove some duplicated code a bit. While at that, also move allocation of struct uart_omap_port higher in the code so that we return much earlier in case of no memory. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: switch over to platform_get_resourceFelipe Balbi1-7/+3
this way we can remove one pointer declaration. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: cleanup variable declarationsFelipe Balbi1-3/+6
cleanup only, no functional changes. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: omap: switch over to devm_request_gpioFelipe Balbi1-2/+3
this will make sure gpio gets freed automatically when this device is destroyed. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: add missing bracesFelipe Balbi1-1/+4
per CodingStyle we should have those braces, no functional changes. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25Revert "serial: omap: unlock the port lock"Felipe Balbi1-4/+1
This reverts commit 0324a821029e1f54e7a7f8fed48693cfce42dc0e. That commit tried to fix a deadlock problem when using hci_ldisc, but it turns out the bug was in hci_ldsic all along where it was calling ->write() from within ->write_wakeup() callback. The problem is that ->write_wakeup() was called with port lock held and ->write() tried to grab the same port lock. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial_core: Commonalize crlf when working w/ a non open console portDoug Anderson5-20/+3
In (efe2f29 kgdboc,kdb: Allow kdb to work on a non open console port) support was added to directly use the "write_char" functions when doing kdb over a non-open console port. This is great, but it ends up bypassing the normal code in uart_console_write() that adds a carriage return before any newlines. There appears to have been a trend to add this support directly in some console driver's poll_put_char() functions. This had a few side effects, including: - In this case we were doing LFCR, not CRLF. This was fixed in uart_console_write() back in (d358788 [SERIAL] kernel console should send CRLF not LFCR) - Not all serial drivers had the LFCR code in their poll_put_char() functions. In my case I was running serial/samsung.c which lacked it. I've moved the handling to uart_poll_put_char() to fix the above problems. Now when I use kdb (and don't point console= to the same UART) I no longer get: [0]kdb> [0]kdb> [0]kdb> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: serial: replace del_timer by del_timer_syncJulia Lawall1-1/+1
Use del_timer_sync to ensure that the timer is stopped on all CPUs before the driver exists. This change was suggested by Thomas Gleixner. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ declarer name module_exit; identifier ex; @@ module_exit(ex); @@ identifier r.ex; @@ ex(...) { <... - del_timer + del_timer_sync (...) ...> } // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: mux: Align SUPPORT_SYSRQ behaviour with other drivers.Daniel Thompson1-1/+1
The mux driver is anomalous among all the serial drivers that can define SUPPORT_SYSRQ because it can, with some configs, set SUPPORT_SYSRQ when SERIAL_CORE_CONSOLE is not set. Not only does this impose a pointless (but tiny) runtime overhead for such configs but, more significantly, it adds needless complexity when doing a code review to check for unexpected side effects of any changes to the serial core. This is (cross-)compile tested only because I do not have any PA-RISC hardware. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: sh-sci: Add device tree support for r8a7779Simon Horman1-1/+9
According to the platform data for the legacy-C initialisation of sh-sci for the r8a7779 SoC and my own testing the SCIx_SH4_SCIF_REGTYPE bit of scscr needs to be set. Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-258250_dw: Support all baudrates on baytrailLoic Poulain1-4/+77
In the same manner as 8250_pci, 8250_dw needs some baytrail specific quirks to be used. The reference clock needs to be adjusted before divided in order to have the minimum error rate on the baudrate. The specific byt set termios function is stored in the driver_data field of the acpi device id via the dw8250_acpi_desc structure. Remove the uartclk field which is no longer delivered as driver data. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25pch_uart: Add uart device to irq nameAlexander Stein1-1/+7
This will additionally show the specific UART device instead of the general module name. This cames in handy so check for the interupts of a specific device if there are several of them. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial_core: fix uart PORT_UNKNOWN handlingThomas Pfaff1-18/+21
While porting a RS485 driver from 2.6.29 to 3.14, i noticed that the serial tty driver could break it by using uart ports that it does not own : 1. uart_change_pm ist called during uart_open and calls the uart pm function without checking for PORT_UNKNOWN. The fix is to move uart_change_pm from uart_open to uart_port_startup. 2. The return code from the uart request_port call in uart_set_info is not handled properly, leading to the situation that the serial driver also thinks it owns the uart ports. This can triggered by doing following actions : setserial /dev/ttyS0 uart none # release the uart ports modprobe lirc-serial # or any other device that uses the uart setserial /dev/ttyS0 uart 16550 # gives no error and the uart tty driver # can use the ports as well Signed-off-by: Thomas Pfaff <tpfaff@pcs.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: samsung: Change barrier() to cpu_relax() in console outputDoug Anderson1-1/+1
The two functions to write out to the console (one used in normal console mode and one in polling console mode) were slightly different. One used a barrier() in its loop and the other a cpu_relax(). The barrier() really doesn't do anything since we're using rd_regl() to read the port anyway. Switch it to cpu_relax() to make things consistent. No known bugs / issues are fixed by this change--it just makes things more consistent. Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: samsung: don't check config for every characterDoug Anderson1-5/+6
The s3c24xx_serial_console_putchar() is _only_ ever used by s3c24xx_serial_console_write() and is called in a loop (indirectly through uart_console_write()). There's no reason to call s3c24xx_port_configured() for every iteration through the loop. Move it outside the loop. Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: samsung: Use the passed in "port", fixing kgdb w/ no consoleDoug Anderson1-6/+6
The two functions in the samsung serial driver used for writing characters out to the port were inconsistent about whether they used the passed in "port" or the global "cons_uart". There was no reason to use the global and the use of the global in s3c24xx_serial_put_poll_char() caused a crash in the case where you used the serial port for kgdboc but not for console. Fix it so we used the passed in variable. Note that this doesn't fix all problems with the samsung serial driver. Specifically: * s3c24xx_serial_console_putchar() is still 99% identical to s3c24xx_serial_put_poll_char() (the function signature is different, but that's about it). A future patch will make them slightly less identical and judging by other serial drivers we may need yet more differences eventually. * The samsung serial driver still doesn't allow you to have more than one console port since it still uses the global cons_uart in s3c24xx_serial_console_write(). Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25serial: 8250: Fix thread unsafe __dma_tx_complete functionLoic Poulain1-2/+7
__dma_tx_complete is not protected against concurrent call of serial8250_tx_dma. it can lead to circular tail index corruption or parallel call of serial_tx_dma on the same data portion. This patch fixes this issue by holding the port lock. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-258250_core: Fix unwanted TX chars writeLoic Poulain1-1/+1
On transmit-hold-register empty, serial8250_tx_chars should be called only if we don't use DMA. DMA has its own tx cycle. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25tty: Fix race condition between __tty_buffer_request_room and flush_to_ldiscManfred Schlaegl1-2/+14
The race was introduced while development of linux-3.11 by e8437d7ecbc50198705331449367d401ebb3181f and e9975fdec0138f1b2a85b9624e41660abd9865d4. Originally it was found and reproduced on linux-3.12.15 and linux-3.12.15-rt25, by sending 500 byte blocks with 115kbaud to the target uart in a loop with 100 milliseconds delay. In short: 1. The consumer flush_to_ldisc is on to remove the head tty_buffer. 2. The producer adds a number of bytes, so that a new tty_buffer must be allocated and added by __tty_buffer_request_room. 3. The consumer removes the head tty_buffer element, without handling newly committed data. Detailed example: * Initial buffer: * Head, Tail -> 0: used=250; commit=250; read=240; next=NULL * Consumer: ''flush_to_ldisc'' * consumed 10 Byte * buffer: * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL {{{ count = head->commit - head->read; // count = 0 if (!count) { // enter // INTERRUPTED BY PRODUCER -> if (head->next == NULL) break; buf->head = head->next; tty_buffer_free(port, head); continue; } }}} * Producer: tty_insert_flip_... 10 bytes + tty_flip_buffer_push * buffer: * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL * added 6 bytes: head-element filled to maximum. * buffer: * Head, Tail -> 0: used=256; commit=250; read=250; next=NULL * added 4 bytes: __tty_buffer_request_room is called * buffer: * Head -> 0: used=256; commit=256; read=250; next=1 * Tail -> 1: used=4; commit=0; read=250 next=NULL * push (tty_flip_buffer_push) * buffer: * Head -> 0: used=256; commit=256; read=250; next=1 * Tail -> 1: used=4; commit=4; read=250 next=NULL * Consumer {{{ count = head->commit - head->read; if (!count) { // INTERRUPTED BY PRODUCER <- if (head->next == NULL) // -> no break break; buf->head = head->next; tty_buffer_free(port, head); // ERROR: tty_buffer head freed -> 6 bytes lost continue; } }}} This patch reintroduces a spin_lock to protect this case. Perhaps later a lock-less solution could be found. Signed-off-by: Manfred Schlaegl <manfred.schlaegl@gmx.at> Cc: stable <stable@vger.kernel.org> # 3.11 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-17Revert "serial: 8250, disable "too much work" messages"Greg Kroah-Hartman1-1/+2
This reverts commit f4f653e9875e573860e783fecbebde284a8626f5. Jiri writes: No, please drop this one. We need a better solution as it turned out that some boxes need 16k loops and it will increase with new processors :(. Cc: Jiri Slaby <jslaby@suse.cz> Cc: Martin Pluskal <mpluskal@suse.com> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-17serial: amba-pl011: fix regression, causing an Oops on rmmodGuennadi Liakhovetski1-1/+5
A recent commit ef2889f7ffee67f0aed49e854c72be63f1466759 "serial: pl011: Move uart_register_driver call to device probe" introduced a regression, causing the pl011 driver to Oops if more than 1 port have been probed. Fix the Oops by only calling uart_unregister_driver() once after the last port has been removed. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-17tty: fix memleak in alloc_pidChen Tingjie1-2/+2
There is memleak in alloc_pid: ------------------------------ unreferenced object 0xd3453a80 (size 64): comm "adbd", pid 1730, jiffies 66363 (age 6586.950s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 40 c2 f6 d5 00 d3 25 c1 59 28 00 00 ....@.....%.Y(.. backtrace: [<c1a6f15c>] kmemleak_alloc+0x3c/0xa0 [<c1320546>] kmem_cache_alloc+0xc6/0x190 [<c125d51e>] alloc_pid+0x1e/0x400 [<c123d344>] copy_process.part.39+0xad4/0x1120 [<c123da59>] do_fork+0x99/0x330 [<c123dd58>] sys_fork+0x28/0x30 [<c1a89a08>] syscall_call+0x7/0xb [<ffffffff>] 0xffffffff the leak is due to unreleased pid->count, which execute in function: get_pid()(pid->count++) and put_pid()(pid->count--). The race condition as following: task[dumpsys] task[adbd] in disassociate_ctty() in tty_signal_session_leader() ----------------------- ------------------------- tty = get_current_tty(); // tty is not NULL ... spin_lock_irq(&current->sighand->siglock); put_pid(current->signal->tty_old_pgrp); current->signal->tty_old_pgrp = NULL; spin_unlock_irq(&current->sighand->siglock); spin_lock_irq(&p->sighand->siglock); ... p->signal->tty = NULL; ... spin_unlock_irq(&p->sighand->siglock); tty = get_current_tty(); // tty NULL, goto else branch by accident. if (tty) { ... put_pid(tty_session); put_pid(tty_pgrp); ... } else { print msg } in task[dumpsys], in disassociate_ctty(), tty is set NULL by task[adbd], tty_signal_session_leader(), then it goto else branch and lack of put_pid(), cause memleak. move spin_unlock(sighand->siglock) after get_current_tty() can avoid the race and fix the memleak. Signed-off-by: Zhang Jun <jun.zhang@intel.com> Signed-off-by: Chen Tingjie <tingjie.chen@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-17serial: 8250, disable "too much work" messagesJiri Slaby1-2/+1
The 8250 driver now reports many of these: serial8250: too much work for irq4 These messages turned out to be common these days with a use of virtualization. I tried to increase the limit of processed characters in commit e7328ae1848966181a7ac47e8ae6cddbd2cf55f3 (serial: 8250, increase PASS_LIMIT) in 2011. It was raised from 256 to 512, but it is still not enough, apparently. So disable the warning unless somebody turns on DEBUG (or DYNAMIC_DEBUG _and_ the message). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Martin Pluskal <mpluskal@suse.com> Reported-by: Takashi Iwai <tiwai@suse.com> Tested-by: Takashi Iwai <tiwai@suse.de> References: https://bugzilla.novell.com/show_bug.cgi?id=868394 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-17serial: omap: Fix missing pm_runtime_resume handling by simplifying codeTony Lindgren1-12/+17
The lack of pm_runtime_resume handling for the device state leads into device wake-up interrupts not working after a while for runtime PM. Also, serial-omap is confused about the use of device_may_wakeup. The checks for device_may_wakeup should only be done for suspend and resume, not for pm_runtime_suspend and pm_runtime_resume. The wake-up events for PM runtime should always be enabled. The lack of pm_runtime_resume handling leads into device wake-up interrupts not working after a while for runtime PM. Rather than try to patch over the issue of adding complex tests to the pm_runtime_resume, let's fix the issues properly: 1. Make serial_omap_enable_wakeup deal with all internal PM state handling so we don't need to test for up->wakeups_enabled elsewhere. Later on once omap3 boots in device tree only mode we can also remove the up->wakeups_enabled flag and rely on the wake-up interrupt enable/disable state alone. 2. Do the device_may_wakeup checks in suspend and resume only, for runtime PM the wake-up events need to be always enabled. 3. Finally just call serial_omap_enable_wakeup and make sure we call it also in pm_runtime_resume. 4. Note that we also have to use disable_irq_nosync as serial_omap_irq calls pm_runtime_get_sync. Fixes: 2a0b965cfb6e (serial: omap: Add support for optional wake-up) Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>