summaryrefslogtreecommitdiffstats
path: root/drivers/serial/8250.c
AgeCommit message (Collapse)Author
2010-11-13Revert "8250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hang"Ingo Molnar
This reverts commit 47d3904fe40d62deee8cd46e79ca784e7a548acd. Crashes any x86 serial console bootup: Console: colour VGA+ 80x25 BUG: unable to handle kernel NULL pointer dereference at 0000000000000158 IP: [<ffffffff811ebcb4>] serial8250_do_set_termios+0x1d4/0x430 ... Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Greg KH <gregkh@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-118250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hangLawrence Rust
Calling tcsetattr prevents any thread(s) currently suspended in ioctl TIOCMIWAIT for the same device from ever resuming. If a thread is suspended inside a call to ioctl TIOCMIWAIT, waiting for a modem status change, then the 8250 driver enables modem status interrupts (MSI). The device interrupt service routine resumes the suspended thread(s) on the next MSI. If while the thread(s) are suspended, another thread calls tcsetattr then the 8250 driver disables MSI (unless CTS/RTS handshaking is enabled) thus preventing the suspended thread(s) from ever being resumed. This patch only disables MSI in tcsetattr handling if there are no suspended threads. Program to demonstrate bug & fix: /* gcc miwait.c -o miwait -l pthread */ #include <stdio.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <pthread.h> #include <termios.h> #include <sys/ioctl.h> #include <linux/serial.h> static void* monitor( void* pv); static int s_fd; int main( void) { const char kszDev[] = "/dev/ttyS0"; pthread_t t; struct termios tio; s_fd = open( kszDev, O_RDWR | O_NONBLOCK); if ( s_fd < 0) return fprintf( stderr, "Error(%d) opening %s: %s\n", errno, kszDev, strerror( errno)), 1; pthread_create( &t, NULL, &monitor, NULL); /* Modem status changes seen here */ puts( "Main: awaiting status changes"); sleep( 5); tcgetattr( s_fd, &tio); tio.c_cflag ^= CSTOPB; /* But not after here */ puts( "Main: tcsetattr called"); tcsetattr( s_fd, TCSANOW, &tio); for (;;) sleep( 1); } static void* monitor( void* pv) { (void)pv; for(;;) { unsigned uModem; struct serial_icounter_struct cnt; if ( ioctl( s_fd, TIOCMGET, &uModem) < 0) fprintf( stderr, "Error(%d) in TIOCMGET: %s\n", errno, strerror( errno)); printf( "Modem status:%s%s%s%s%s%s\n", (uModem & TIOCM_RTS) ? " RTS" : "", (uModem & TIOCM_DTR) ? " DTR" : "", (uModem & TIOCM_CTS) ? " CTS" : "", (uModem & TIOCM_DSR) ? " DSR" : "", (uModem & TIOCM_CD) ? " CD" : "", (uModem & TIOCM_RI) ? " RI" : "" ); if ( ioctl( s_fd, TIOCGICOUNT, &cnt) < 0) fprintf( stderr, "Error(%d) in TIOCGICOUNT: %s\n", errno, strerror( errno)); printf( "Irqs: CTS:%d DSR:%d RNG:%d DCD:%d Rx:%d Tx:%d Frame:%d Orun:%d Par:%d Brk:%d Oflow:%d\n", cnt.cts, cnt.dsr, cnt.rng, cnt.dcd, cnt.rx, cnt.tx, cnt.frame, cnt.overrun, cnt.parity, cnt.brk, cnt.buf_overrun ); fputs( "Waiting...", stdout), fflush( stdout); if ( 0 > ioctl( s_fd, TIOCMIWAIT, (unsigned long)(TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS))) fprintf( stderr, "\nError(%d) in TIOCMIWAIT: %s\n", errno, strerror( errno)); fputs( "\n", stdout); } return NULL; } Signed-off by Lawrence Rust <lawrence@softsystem.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-24Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Update broken web addresses in arch directory. Update broken web addresses in the kernel. Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget Revert "Fix typo: configuation => configuration" partially ida: document IDA_BITMAP_LONGS calculation ext2: fix a typo on comment in ext2/inode.c drivers/scsi: Remove unnecessary casts of private_data drivers/s390: Remove unnecessary casts of private_data net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data drivers/infiniband: Remove unnecessary casts of private_data drivers/gpu/drm: Remove unnecessary casts of private_data kernel/pm_qos_params.c: Remove unnecessary casts of private_data fs/ecryptfs: Remove unnecessary casts of private_data fs/seq_file.c: Remove unnecessary casts of private_data arm: uengine.c: remove C99 comments arm: scoop.c: remove C99 comments Fix typo configue => configure in comments Fix typo: configuation => configuration Fix typo interrest[ing|ed] => interest[ing|ed] Fix various typos of valid in comments ... Fix up trivial conflicts in: drivers/char/ipmi/ipmi_si_intf.c drivers/usb/gadget/rndis.c net/irda/irnet/irnet_ppp.c
2010-10-22serial8250: ratelimit "too much work" errorDaniel Drake
Running a serial console, if too many kernel messages are generated within a short time causing a lot of serial I/O, the 8250 driver will generate another kernel message reporting this, which just adds to the I/O. It has a cascading effect and quickly results the system being brought to its knees by a flood of "too much work" messages. Ratelimit the error message to avoid this. [akpm@linux-foundation.org: use the superior printk_ratelimited()] [akpm@linux-foundation.org: printk_ratelimited() needs ratelimit.h] Signed-off-by: Daniel Drake <dsd@laptop.org> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22serial: abstraction for 8250 legacy portsAlan Cox
Not every platform that has generic legacy 8250 ports manages to have them clocked the right way or without errata. Provide a generic interface to allow platforms to override the default behaviour in a manner that dumps the complexity in *their* code not the 8250 driver. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-228250: allow platforms to override PM hook.Manuel Lauss
Add a hook for platforms to specify custom pm methods. Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22serial: Factor out uart_poll_timeout() from 8250 driverAnton Vorontsov
Soon we will use that handy function in the altera_uart driver. Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22serial: 8250: Don't delay after transmitter is ready.David Daney
The loop in wait_for_xmitr() is delaying one extra uS after the ready condition has been met. Rewrite the loop to only delay if the transmitter is not ready. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-18Update broken web addresses in the kernel.Justin P. Mattock
The patch below updates broken web addresses in the kernel Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Dimitry Torokhov <dmitry.torokhov@gmail.com> Cc: Mike Frysinger <vapier.adi@gmail.com> Acked-by: Ben Pfaff <blp@cs.stanford.edu> Acked-by: Hans J. Koch <hjk@linutronix.de> Reviewed-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-10U6715 16550A serial driver supportPhilippe Langlais
UART Features extract from STEricsson U6715 data-sheet (arm926 SoC for mobile phone): * Fully compatible with industry standard 16C550 and 16C450 from various manufacturers * RX and TX 64 byte FIFO reduces CPU interrupts * Full double buffering * Modem control signals include CTS, RTS, (and DSR, DTR on UART1 only) * Automatic baud rate selection * Manual or automatic RTS/CTS smart hardware flow control * Programmable serial characteristics: – Baud rate generation (50 to 3.25M baud) – 5, 6, 7 or 8-bit characters – Even, odd or no-parity bit generation and detection – 1, 1.5 or 2 stop bit generation * Independent control of transmit, receive, line status, data set interrupts and FIFOs * Full status-reporting capabilities * Separate DMA signaling for RX and TX * Timed interrupt to spread receive interrupt on known duration * DMA time-out interrupt to allow detection of end of reception * Carkit pulse coding and decoding compliant with USB carkit control interface [40] In 16550A auto-configuration, if the fifo size is 64 then it's an U6 16550A port Add set_termios hook & export serial8250_do_set_termios to change uart clock following baudrate Signed-off-by: Philippe Langlais <philippe.langlais@stericsson.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-108250: fix set_ldisc operationArnd Bergmann
The ldisc number now gets passed into ->set_ldisc. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10serial: add UART_CAP_EFR and UART_CAP_SLEEP flags to 16C950 UARTs definitionYegor Yefremov
Adding UART_CAP_EFR and UART_CAP_SLEEP flags will enable sleep mode and automatic CTS flow control for 16C950 UARTs. It will also avoid capabilities detection warning like this: "ttyS0: detected caps 00000700 should be 00000100" Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05SERIAL: 8250: Remove SERIAL_8250_AU1X00Manuel Lauss
Remove the SERIAL_8250_AU1X00 config symbol. Instead, use the MIPS_ALCHEMY one which is always defined when building an Au1x00-based platform. Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com> To: Linux-MIPS <linux-mips@linux-mips.org> Cc: Linux-serial <linux-serial@vger.kernel.org> Patchwork: https://patchwork.linux-mips.org/patch/1461/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> This one depends on a previous patch (which removes SOC_AU1X00 and changes MACH_ALCHEMY) to apply cleanly (and then actually work), so I'd love for this to go in via the mips tree.
2010-05-20kgdb,8250,pl011: Return immediately from console pollJason Wessel
The design of the kdb shell requires that every device that can provide input to kdb have a polling routine that exits immediately if there is no character available. This is required in order to get the page scrolling mechanism working. Changing the kernel debugger I/O API to require all polling character routines to exit immediately if there is no data allows the kernel debugger to process multiple input channels. NO_POLL_CHAR will be the return code to the polling routine when ever there is no character available. CC: linux-serial@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-12serial 8250: enable PPS supportRodolfo Giometti
Automagically function serial8250_enable_ms() is called when PPS ldisc is selected. Signed-off-by: Rodolfo Giometti <giometti@linux.it> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg KH <greg@kroah.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-02serial: copy UART properties of UPF_FIXED_TYPE ports provisioned using ↵Shmulik Ladkani
early_serial_setup Augment the UPF_FIXED_TYPE logic, which currently applies to UART ports provisioned using platform_device_register. The suggested patch applies same logic into 'serial8250_register_ports', making UART ports provisioned using early_serial_setup inherit their properties from the uart_config entry. Signed-off-by: Shmulik Ladkani <shmulik@jungo.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-27SERIAL 8250: Fixes for Alchemy UARTs.Manuel Lauss
Limit the amount of address space claimed for Alchemy serial ports to 0x1000. On the Au1300, ports are only 0x1000 apart, and the registers only extend to 0x110 at most on all supported alchemy models. On the Au1300 the autodetect logic no longer works and this makes it necessary to specify the port type through platform data. Because of this the MSR quirk needs to be moved outside the autoconfig() function which will no longer be called when UPF_FIXED_TYPE is specified. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org>, Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-16serial: 8250: add serial transmitter fully empty testDick Hollenbeck
When controlling an industrial radio modem it can be necessary to manipulate the handshake lines in order to control the radio modem's transmitter, from userspace. The transmitter should not be turned off before all characters have been transmitted. serial8250_tx_empty() was reporting that all characters were transmitted before they actually were. === Discovered in parallel with more testing and analysis by Kees Schoenmakers as follows: I ran into an NetMos 9835 serial pci board which behaves a little different than the standard. This type of expansion board is very common. "Standard" 8250 compatible devices clear the 'UART_LST_TEMT" bit together with the "UART_LSR_THRE" bit when writing data to the device. The NetMos device does it slightly different I believe that the TEMT bit is coupled to the shift register. The problem is that after writing data to the device and very quickly after that one does call serial8250_tx_empty, it returns the wrong information. My patch makes the test more robust (and solves the problem) and it does not affect the already correct devices. Alan: We may yet need to quirk this but now we know which chips we have a way to do that should we find this breaks some other 8250 clone with dodgy THRE. Signed-off-by: Dick Hollenbeck <dick@softplc.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Kees Schoenmakers <k.schoenmakers@sigmae.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11Serial: Do not read IIR in serial8250_start_tx when UART_BUG_TXENIan Jackson
Do not read IIR in serial8250_start_tx when UART_BUG_TXEN Reading the IIR clears some oustanding interrupts so it is not safe. Instead, simply transmit immediately if the buffer is empty without regard to IIR. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11serial, 8250: calculate irqflags bitmask before loopAndré Goddard Rosa
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-11-12serial: fix printk format specifiers for struct uart_port::iobaseLennert Buytenhek
struct uart_port::iobase is unsigned long, so use %lx as printk format specifier. Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01serial: add parameter to force skipping the test for the TXEN bugChuck Ebbert
Allow users to force skipping the TXEN test at init time. Applies to all serial ports. Intended for debugging only. There is a blacklist for devices where we need to skip the test but the list is not complete. This lets users force skipping the test so we can determine if they need to be added to the list. Some HP machines with weird serial consoles have this problem and there may be more. Signed-off-by: Chuck Ebbert <cebbert@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-19serial: move delta_msr_wait into the tty_portAlan Cox
This is used by various drivers not just serial and can be extracted as commonality Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19serial: kill off uart_infoAlan Cox
We moved this into uart_state, now move the fields out of the separate structure and kill it off. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-198250: Now honours baud rate lower boundsAnton Vorontsov
A platform clock drives 8250 ports in most SOC systems, the clock might run at high frequencies, and so it's not always possible to downscale uart clock to a desired value. Currently the 8250 uart driver accepts not supported baud rates, and what is worse, it is doing this silently, and then passes not accepted values to a new termios, so userspace has no chance to catch this kind of errors (userspace verifies that settings were accepted by reading back and comparing the settings). This patch fixes the issue by passing minimum baud rate to the uart_get_baud_rate() call, the call should take care of all bounds, so userspace should now report: # stty -F /dev/ttyS0 speed 300 115200 stty: /dev/ttyS0: unable to perform all requested operations p.s. uart_get_baud_rate() falls back to 9600, which still might be too low for some 10 GHz platforms, but that's a separate issue, and we can wait with fixing this till we find such a platform. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19serial: 8250: add IRQ trigger supportVikram Pandita
There is currently no provision for passing IRQ trigger flags for serial IRQs with triggering requirements (such as GPIO IRQs) This patch adds irqflags to plat_serial8250_port that can be passed from board file to reqest_irq() of 8250 driver Changes are backward compatible with boards passing UPF_SHARE_IRQ flag Tested on Zoom2 board that has IRQF_TRIGGER_RISING requirement for 8250 irq [Moved new flag to end to fix bugs in the original with the old_serial array -- Alan] Signed-off-by: Vikram Pandita <vikram.pandita@ti.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-11serial: add support for the TI AR7 internal UARTFlorian Fainelli
This patch adds support for the TI AR7 internal UART. Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-298250: Fix oops from setserialAlan Cox
If you setserial a port which has never been initialised we change the type but don't update the I/O method pointers. The same problem is true if you change the io type of a port - but nobody ever does that so nobody noticed! Remember the old type and when attaching if the type has changed reload the port accessor pointers. We can't do it blindly as some 8250 drivers load custom accessors and we must not stomp those. Tested-by: Victor Seryodkin <vvscore@gmail.com> Closes-bug: #13367 Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-208250: fix boot hang with serial console when using with Serial Over Lan portMauro Carvalho Chehab
Intel 8257x Ethernet boards have a feature called Serial Over Lan. This feature works by emulating a serial port, and it is detected by kernel as a normal 8250 port. However, this emulation is not perfect, as also noticed on changeset 7500b1f602aad75901774a67a687ee985d85893f. Before this patch, the kernel were trying to check if the serial TX is capable of work using IRQ's. This were done with a code similar this: serial_outp(up, UART_IER, UART_IER_THRI); lsr = serial_in(up, UART_LSR); iir = serial_in(up, UART_IIR); serial_outp(up, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) up->bugs |= UART_BUG_TXEN; This works fine for other 8250 ports, but, on 8250-emulated SoL port, the chip is a little lazy to down UART_IIR_NO_INT at UART_IIR register. Due to that, UART_BUG_TXEN is sometimes enabled. However, as TX IRQ keeps working, and the TX polling is now enabled, the driver miss-interprets the IRQ received later, hanging up the machine until a key is pressed at the serial console. This is the 6 version of this patch. Previous versions were trying to introduce a large enough delay between serial_outp and serial_in(up, UART_IIR), but not taking forever. However, the needed delay couldn't be safely determined. At the experimental tests, a delay of 1us solves most of the cases, but still hangs sometimes. Increasing the delay to 5us was better, but still doesn't solve. A very high delay of 50 ms seemed to work every time. However, poking around with delays and pray for it to be enough doesn't seem to be a good approach, even for a quirk. So, instead of playing with random large arbitrary delays, let's just disable UART_BUG_TXEN for all SoL ports. [akpm@linux-foundation.org: fix warnings] Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-13fix early_serial_setup() regressionHelge Deller
Commit b430428a188e8a434325e251d0704af4b88b4711 ("8250: Don't clobber spinlocks.") introduced a regression on the parisc architecture, which broke the handover to the serial port at boottime. early_serial_setup() was changed to only copy a subset of the uart_port fields, and sadly the "type" and "line" fields were forgotten and thus the serial port was not initialized and could not be used for a handover. This patch fixes this by copying the missing fields. As this change to early_serial_setup() doesn't need an initialized spinlock in the uart_port struct any longer, we can drop the spinlock initialization in the superio driver. Cc: David Daney <ddaney@caviumnetworks.com> Cc: Tomaso Paoletti <tpaoletti@caviumnetworks.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Cc: linux-parisc@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06trivial: Add a space (and a comma) to a printk in 8250 driverPaul Bolle
Commit d87a6d9 ("drivers/serial/: remove CVS keywords") removed one space too many in the printk in serial8250_init(). Put it back in (and add a comma for clarity). Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-02Serial: UART driver changes for Cavium OCTEON.David Daney
Cavium UART implementation is not covered by existing uart_configS. Define a new uart_config (PORT_OCTEON) which is specified by OCTEON platform device registration code. Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com> Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02Serial: Allow port type to be specified when calling serial8250_register_port.David Daney
Add flag value UPF_FIXED_TYPE which specifies that the UART type is known and should not be probed. For this case the UARTs properties are just copied out of the uart_config entry. This allows us to keep SOC specific 8250 probe code out of 8250.c. In this case we know the serial hardware will not be changing as it is on the same silicon as the CPU, and we can specify it with certainty in the board/cpu setup code. The alternative is to load up 8250.c with a bunch of OCTEON specific special cases in the probing code. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-028250: Serial driver changes to support future Cavium OCTEON serial patches.David Daney
In order to use Cavium OCTEON specific serial i/o drivers, we first patch the 8250 driver to use replaceable I/O functions. Compatible I/O functions are added for existing iotypeS. An added benefit of this change is that it makes it easy to factor some of the existing special cases out to board/SOC specific support code. The alternative is to load up 8250.c with a bunch of OCTEON specific iotype code and bug work-arounds. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-028250: Don't clobber spinlocks.David Daney
In serial8250_isa_init_ports(), the port's lock is initialized. We should not overwrite it. In early_serial_setup(), only copy in the fields we need. Since the early console code only uses a subset of the fields, these are sufficient. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20Merge branch 'genirq-v28-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu and x86/uv. The sparseirq branch is just preliminary groundwork: no sparse IRQs are actually implemented by this tree anymore - just the new APIs are added while keeping the old way intact as well (the new APIs map 1:1 to irq_desc[]). The 'real' sparse IRQ support will then be a relatively small patch ontop of this - with a v2.6.29 merge target. * 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits) genirq: improve include files intr_remapping: fix typo io_apic: make irq_mis_count available on 64-bit too genirq: fix name space collisions of nr_irqs in arch/* genirq: fix name space collision of nr_irqs in autoprobe.c genirq: use iterators for irq_desc loops proc: fixup irq iterator genirq: add reverse iterator for irq_desc x86: move ack_bad_irq() to irq.c x86: unify show_interrupts() and proc helpers x86: cleanup show_interrupts genirq: cleanup the sparseirq modifications genirq: remove artifacts from sparseirq removal genirq: revert dynarray genirq: remove irq_to_desc_alloc genirq: remove sparse irq code genirq: use inline function for irq_to_desc genirq: consolidate nr_irqs and for_each_irq_desc() x86: remove sparse irq from Kconfig genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n ...
2008-10-16Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (51 commits) [ARM] 5308/1: Fix Viper ISA IRQ handling [ARM] 5307/1: pxa: fix CM-X2XX PCMCIA build error [ARM] 5306/1: pxa: fix build error on CM-X270 [ARM] 5302/1: ARM: OMAP: Revert omap3 WDT changes to avoid merge conflict [ARM] 5305/1: ARM: OMAP: Fix compile of McBSP by removing unnecessary check [ARM] 5301/1: ARM: OMAP: Add missing irq defines ARM: OMAP3: Add default kernel config for OMAP LDP ARM: OMAP3: Add basic board support for OMAP LDP ARM: OMAP3: Defconfig for the Gumstix Overo board (rev 3) ARM: OMAP3: Add support for the Gumstix Overo board (rev 3) ARM: OMAP3: Add Beagle defconfig ARM: OMAP3: Add minimal Beagle board support ARM: OMAP3: Add minimal omap3430 support ARM: OMAP2: Fix sparse, checkpatch warnings in OMAP2/3 IRQ code ARM: OMAP: Fixes to omap_mcbsp_request function ARM: OMAP: Add support for OMAP2430 in McBSP ARM: OMAP: Add support for McBSP devices 3 - 5 on 34xx ARM: OMAP: Allocate McBSP devices dynamically Fix sections for omap-mcbsp platform driver [ARM] S3C24XX: Additional include moves ...
2008-10-16drivers/serial: use nr_irqsYinghai Lu
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16serial, 8250: remove NR_IRQ usageAlan Cox
Works on my test box with a quick test. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-15Merge branch 'fixes' into for-linusRussell King
Conflicts: arch/arm/mach-versatile/core.c
2008-10-148250: Fix lock warning (and possible crash)Alan Cox
Splitting the 8250 code back up to avoid a clash with the NR_IRQS removal patch introduced a last minute bug. Put back the additional needed lines for the old lock init Signed-off-by: Alan Cox <alan@redhat.com> [ Ingo also reports that this can cause a spontaneous reboot crash with certain configs, and sends in an identical patch ] Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13serial: fix device name reporting when minor space is shared between driversDavid S. Miller
The multiple drivers share the minor space occupied by a particular major number, the actual index within the device name's space is indicated by the tty_driver->name_base + uart_port->line Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line Use those to print the device names properly in such situations in serial_core.c and 8250.c Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13serial: allow 8250 to be used on sparcDavid Miller
This requires three changes: 1) Remove !SPARC restriction in Kconfig. 2) Move Sparc specific serial drivers before 8250, so that serial console devices don't change names on us, even if 8250 finds devices. 3) Since the Sparc specific serial drivers try to use the same major/minor device namespace as 8250, some coordination is necessary. Use the sunserial_*() layer routines to allocate minor number space within TTY_MAJOR when CONFIG_SPARC. This has no effect on other platforms. Thanks to Josip Rodin for bringing up this issue and testing plus debugging various revisions of this patch. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-138250: remove a few inlines of dubious valueWill Newton
Remove some inlines from various functions that are called once, are too big to inline, or are called only from slow path code. This saves around 300 bytes of code for me. Signed-off-by: Will Newton <will.newton@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-05[SERIAL] 8250: serial8250_port_size() - omap ports are largerRussell King
A function to contain common code for the size of the resource we need to allocate or free. OMAP ports need 22 bytes rather than the standard 8 bytes. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-05[ARM] omap: improve is_omap_port()Russell King
Make is_omap_port() take the uart_8250_port structure so it can do whatever test it desires. Convert the test to compare the physical addresses rather than virtual addresses. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-028250: improve workaround for UARTs that don't re-assert THRE correctlyWill Newton
Recent changes to tighten the check for UARTs that don't correctly re-assert THRE (01c194d9278efc15d4785ff205643e9c0bdcef53: "serial 8250: tighten test for using backup timer") caused problems when such a UART was opened for the second time - the bug could only successfully be detected at first initialization. For users of this version of this particular UART IP it is fatal. This patch stores the information about the bug in the bugs field of the port structure when the port is first started up so subsequent opens can check this bit even if the test for the bug fails. David Brownell: "My own exposure to this is that the UART on DaVinci hardware, which TI allegedly derived from its original 16550 logic, has periodically gone from working to unusable with the mainline 8250.c ... and back and forth a bunch. Currently it's "unusable", a regression from some previous versions. With this patch from Will, it's usable." Signed-off-by: Will Newton <will.newton@gmail.com> Acked-by: Alex Williamson <alex.williamson@hp.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Brownell <david-b@pacbell.net> Cc: <stable@kernel.org> [2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-308250.c: port.lock is irq-safeBorislav Petkov
serial8250_startup() doesn't disable interrupts while taking the &up->port.lock which might race against the interrupt handler serial8250_interrupt(), which when entered, will deadlock waiting for the lock to be released. Signed-off-by: Borislav Petkov <petkovbb@gmail.com> Tested-by: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-248250: fix break handling for Intel 82571Aristeu Rozanski
Intel 82571 has a "Serial Over LAN" feature that doesn't properly implements the receiving of break characters. When a break is received, it doesn't set UART_LSR_DR and unless another character is received, the break won't be received by the application. Signed-off-by: Aristeu Rozanski <arozansk@redhat.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>