linux-stable.git/drivers/tty, branch linux-3.2.y Linux kernel stable tree tty: vt: fix up tabstops properly 2018-05-31T23:30:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-03-24T09:43:26+00:00 303f7c4c27da1ba0d54c62eb1ae66330bc1c835e commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream. Tabs on a console with long lines do not wrap properly, so correctly account for the line length when computing the tab placement location. Reported-by: James Holderness <j4_james@hotmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream.

Tabs on a console with long lines do not wrap properly, so correctly
account for the line length when computing the tab placement location.

Reported-by: James Holderness <j4_james@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: sh-sci: prevent lockup on full TTY buffers 2018-05-31T23:30:19+00:00 Ulrich Hecht ulrich.hecht+renesas@gmail.com 2018-02-15T12:02:27+00:00 1063c9391c430f0059780c55be0874dce91e59d2 commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream. 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> Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: - Use sci_in() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream.

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>
Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
 - Use sci_in()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tty: make n_tty_read() always abort if hangup is in progress 2018-05-31T23:30:19+00:00 Tejun Heo tj@kernel.org 2018-02-13T15:38:08+00:00 50bf8fc9a9a95b1c97b79278177a2378f4c7d6ad commit 28b0f8a6962a24ed21737578f3b1b07424635c9e upstream. A tty is hung up by __tty_hangup() setting file->f_op to hung_up_tty_fops, which is skipped on ttys whose write operation isn't tty_write(). This means that, for example, /dev/console whose write op is redirected_tty_write() is never actually marked hung up. Because n_tty_read() uses the hung up status to decide whether to abort the waiting readers, the lack of hung-up marking can lead to the following scenario. 1. A session contains two processes. The leader and its child. The child ignores SIGHUP. 2. The leader exits and starts disassociating from the controlling terminal (/dev/console). 3. __tty_hangup() skips setting f_op to hung_up_tty_fops. 4. SIGHUP is delivered and ignored. 5. tty_ldisc_hangup() is invoked. It wakes up the waits which should clear the read lockers of tty->ldisc_sem. 6. The reader wakes up but because tty_hung_up_p() is false, it doesn't abort and goes back to sleep while read-holding tty->ldisc_sem. 7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup() and is now stuck in D sleep indefinitely waiting for tty->ldisc_sem. The following is Alan's explanation on why some ttys aren't hung up. http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop 1. It broke the serial consoles because they would hang up and close down the hardware. With tty_port that *should* be fixable properly for any cases remaining. 2. The console layer was (and still is) completely broken and doens't refcount properly. So if you turn on console hangups it breaks (as indeed does freeing consoles and half a dozen other things). As neither can be fixed quickly, this patch works around the problem by introducing a new flag, TTY_HUPPING, which is used solely to tell n_tty_read() that hang-up is in progress for the console and the readers should be aborted regardless of the hung-up status of the device. The following is a sample hung task warning caused by this issue. INFO: task agetty:2662 blocked for more than 120 seconds. Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 0 2662 1 0x00000086 Call Trace: __schedule+0x267/0x890 schedule+0x36/0x80 schedule_timeout+0x23c/0x2e0 ldsem_down_write+0xce/0x1f6 tty_ldisc_lock+0x16/0x30 tty_ldisc_hangup+0xb3/0x1b0 __tty_hangup+0x300/0x410 disassociate_ctty+0x6c/0x290 do_exit+0x7ef/0xb00 do_group_exit+0x3f/0xa0 get_signal+0x1b3/0x5d0 do_signal+0x28/0x660 exit_to_usermode_loop+0x46/0x86 do_syscall_64+0x9c/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 The following is the repro. Run "$PROG /dev/console". The parent process hangs in D state. #include <sys/types.h> #include <sys/stat.h> #include <sys/wait.h> #include <sys/ioctl.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <signal.h> #include <time.h> #include <termios.h> int main(int argc, char **argv) { struct sigaction sact = { .sa_handler = SIG_IGN }; struct timespec ts1s = { .tv_sec = 1 }; pid_t pid; int fd; if (argc < 2) { fprintf(stderr, "test-hung-tty /dev/$TTY\n"); return 1; } /* fork a child to ensure that it isn't already the session leader */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { /* top parent, wait for everyone */ while (waitpid(-1, NULL, 0) >= 0) ; if (errno != ECHILD) perror("waitpid"); return 0; } /* new session, start a new session and set the controlling tty */ if (setsid() < 0) { perror("setsid"); return 1; } fd = open(argv[1], O_RDWR); if (fd < 0) { perror("open"); return 1; } if (ioctl(fd, TIOCSCTTY, 1) < 0) { perror("ioctl"); return 1; } /* fork a child, sleep a bit and exit */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { nanosleep(&ts1s, NULL); printf("Session leader exiting\n"); exit(0); } /* * The child ignores SIGHUP and keeps reading from the controlling * tty. Because SIGHUP is ignored, the child doesn't get killed on * parent exit and the bug in n_tty makes the read(2) block the * parent's control terminal hangup attempt. The parent ends up in * D sleep until the child is explicitly killed. */ sigaction(SIGHUP, &sact, NULL); printf("Child reading tty\n"); while (1) { char buf[1024]; if (read(fd, buf, sizeof(buf)) < 0) { perror("read"); return 1; } } return 0; } Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Cox <alan@llwyncelyn.cymru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: TTY_HUPPING is not really a new flag; it's an old flag that was wrongly removed in 3.19. Just add the test for it in n_tty_read().] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 28b0f8a6962a24ed21737578f3b1b07424635c9e upstream.

A tty is hung up by __tty_hangup() setting file->f_op to
hung_up_tty_fops, which is skipped on ttys whose write operation isn't
tty_write().  This means that, for example, /dev/console whose write
op is redirected_tty_write() is never actually marked hung up.

Because n_tty_read() uses the hung up status to decide whether to
abort the waiting readers, the lack of hung-up marking can lead to the
following scenario.

 1. A session contains two processes.  The leader and its child.  The
    child ignores SIGHUP.

 2. The leader exits and starts disassociating from the controlling
    terminal (/dev/console).

 3. __tty_hangup() skips setting f_op to hung_up_tty_fops.

 4. SIGHUP is delivered and ignored.

 5. tty_ldisc_hangup() is invoked.  It wakes up the waits which should
    clear the read lockers of tty->ldisc_sem.

 6. The reader wakes up but because tty_hung_up_p() is false, it
    doesn't abort and goes back to sleep while read-holding
    tty->ldisc_sem.

 7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup()
    and is now stuck in D sleep indefinitely waiting for
    tty->ldisc_sem.

The following is Alan's explanation on why some ttys aren't hung up.

 http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop

 1. It broke the serial consoles because they would hang up and close
    down the hardware. With tty_port that *should* be fixable properly
    for any cases remaining.

 2. The console layer was (and still is) completely broken and doens't
    refcount properly. So if you turn on console hangups it breaks (as
    indeed does freeing consoles and half a dozen other things).

As neither can be fixed quickly, this patch works around the problem
by introducing a new flag, TTY_HUPPING, which is used solely to tell
n_tty_read() that hang-up is in progress for the console and the
readers should be aborted regardless of the hung-up status of the
device.

The following is a sample hung task warning caused by this issue.

  INFO: task agetty:2662 blocked for more than 120 seconds.
        Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
      0  2662      1 0x00000086
  Call Trace:
   __schedule+0x267/0x890
   schedule+0x36/0x80
   schedule_timeout+0x23c/0x2e0
   ldsem_down_write+0xce/0x1f6
   tty_ldisc_lock+0x16/0x30
   tty_ldisc_hangup+0xb3/0x1b0
   __tty_hangup+0x300/0x410
   disassociate_ctty+0x6c/0x290
   do_exit+0x7ef/0xb00
   do_group_exit+0x3f/0xa0
   get_signal+0x1b3/0x5d0
   do_signal+0x28/0x660
   exit_to_usermode_loop+0x46/0x86
   do_syscall_64+0x9c/0xb0
   entry_SYSCALL64_slow_path+0x25/0x25

The following is the repro.  Run "$PROG /dev/console".  The parent
process hangs in D state.

  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/wait.h>
  #include <sys/ioctl.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <errno.h>
  #include <signal.h>
  #include <time.h>
  #include <termios.h>

  int main(int argc, char **argv)
  {
	  struct sigaction sact = { .sa_handler = SIG_IGN };
	  struct timespec ts1s = { .tv_sec = 1 };
	  pid_t pid;
	  int fd;

	  if (argc < 2) {
		  fprintf(stderr, "test-hung-tty /dev/$TTY\n");
		  return 1;
	  }

	  /* fork a child to ensure that it isn't already the session leader */
	  pid = fork();
	  if (pid < 0) {
		  perror("fork");
		  return 1;
	  }

	  if (pid > 0) {
		  /* top parent, wait for everyone */
		  while (waitpid(-1, NULL, 0) >= 0)
			  ;
		  if (errno != ECHILD)
			  perror("waitpid");
		  return 0;
	  }

	  /* new session, start a new session and set the controlling tty */
	  if (setsid() < 0) {
		  perror("setsid");
		  return 1;
	  }

	  fd = open(argv[1], O_RDWR);
	  if (fd < 0) {
		  perror("open");
		  return 1;
	  }

	  if (ioctl(fd, TIOCSCTTY, 1) < 0) {
		  perror("ioctl");
		  return 1;
	  }

	  /* fork a child, sleep a bit and exit */
	  pid = fork();
	  if (pid < 0) {
		  perror("fork");
		  return 1;
	  }

	  if (pid > 0) {
		  nanosleep(&ts1s, NULL);
		  printf("Session leader exiting\n");
		  exit(0);
	  }

	  /*
	   * The child ignores SIGHUP and keeps reading from the controlling
	   * tty.  Because SIGHUP is ignored, the child doesn't get killed on
	   * parent exit and the bug in n_tty makes the read(2) block the
	   * parent's control terminal hangup attempt.  The parent ends up in
	   * D sleep until the child is explicitly killed.
	   */
	  sigaction(SIGHUP, &sact, NULL);
	  printf("Child reading tty\n");
	  while (1) {
		  char buf[1024];

		  if (read(fd, buf, sizeof(buf)) < 0) {
			  perror("read");
			  return 1;
		  }
	  }

	  return 0;
  }

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: TTY_HUPPING is not really a new flag; it's an old flag
 that was wrongly removed in 3.19.  Just add the test for it in n_tty_read().]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD) 2018-03-03T15:50:51+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-12-21T01:57:06+00:00 8711719778f9e003be82bba0362e87b97b46c891 commit 966031f340185eddd05affcf72b740549f056348 upstream. We added support for EXTPROC back in 2010 in commit 26df6d13406d ("tty: Add EXTPROC support for LINEMODE") and the intent was to allow it to override some (all?) ICANON behavior. Quoting from that original commit message: There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. but the problem turns out that "several aspects of the terminal driver are disabled" is a bit ambiguous, and you can really confuse the n_tty layer by setting EXTPROC and then causing some of the ICANON invariants to no longer be maintained. This fixes at least one such case (TIOCINQ) becoming unhappy because of the confusion over whether ICANON really means ICANON when EXTPROC is set. This basically makes TIOCINQ match the case of read: if EXTPROC is set, we ignore ICANON. Also, make sure to reset the ICANON state ie EXTPROC changes, not just if ICANON changes. Fixes: 26df6d13406d ("tty: Add EXTPROC support for LINEMODE") Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 966031f340185eddd05affcf72b740549f056348 upstream.

We added support for EXTPROC back in 2010 in commit 26df6d13406d ("tty:
Add EXTPROC support for LINEMODE") and the intent was to allow it to
override some (all?) ICANON behavior.  Quoting from that original commit
message:

         There is a new bit in the termios local flag word, EXTPROC.
         When this bit is set, several aspects of the terminal driver
         are disabled.  Input line editing, character echo, and mapping
         of signals are all disabled.  This allows the telnetd to turn
         off these functions when in linemode, but still keep track of
         what state the user wants the terminal to be in.

but the problem turns out that "several aspects of the terminal driver
are disabled" is a bit ambiguous, and you can really confuse the n_tty
layer by setting EXTPROC and then causing some of the ICANON invariants
to no longer be maintained.

This fixes at least one such case (TIOCINQ) becoming unhappy because of
the confusion over whether ICANON really means ICANON when EXTPROC is set.

This basically makes TIOCINQ match the case of read: if EXTPROC is set,
we ignore ICANON.  Also, make sure to reset the ICANON state ie EXTPROC
changes, not just if ICANON changes.

Fixes: 26df6d13406d ("tty: Add EXTPROC support for LINEMODE")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: 8250_pci: Add Amazon PCI serial device ID 2018-03-03T15:50:40+00:00 Matt Wilson msw@amazon.com 2017-11-13T19:31:31+00:00 d8628fe8c50bdcd7060e3038ac5518fc9dfb5711 commit 3bfd1300abfe3adb18e84a89d97a0e82a22124bb upstream. 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 Signed-off-by: Matt Wilson <msw@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 3bfd1300abfe3adb18e84a89d97a0e82a22124bb upstream.

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

Signed-off-by: Matt Wilson <msw@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
vt: fix unchecked __put_user() in tioclinux ioctls 2017-10-12T14:27:17+00:00 Adam Borowski kilobyte@angband.pl 2017-06-03T07:35:06+00:00 65e992fc50593ad2fac03c0e4a682fb871b65336 commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream. Only read access is checked before this call. Actually, at the moment this is not an issue, as every in-tree arch does the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU to tell them apart, but this wasn't the case in the past and may happen again on some odd arch in the future. If anyone cares about 3.7 and earlier, this is a security hole (untested) on real 80386 CPUs. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream.

Only read access is checked before this call.

Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.

If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: sh-sci: Fix panic when serial console and DMA are enabled 2017-08-26T01:13:57+00:00 Takatoshi Akiyama takatoshi.akiyama.kj@ps.hitachi-solutions.com 2017-02-27T06:56:31+00:00 135e5d48d5340a13dde43d38193fb58f661e8d47 commit 3c9101766b502a0163d1d437fada5801cf616be2 upstream. This patch fixes an issue that kernel panic happens when DMA is enabled and we press enter key while the kernel booting on the serial console. * An interrupt may occur after sci_request_irq(). * DMA transfer area is initialized by setup_timer() in sci_request_dma() and used in interrupt. If an interrupt occurred between sci_request_irq() and setup_timer() in sci_request_dma(), DMA transfer area has not been initialized yet. So, this patch changes the order of sci_request_irq() and sci_request_dma(). Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.") Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com> [Shimoda changes the commit log] Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 3c9101766b502a0163d1d437fada5801cf616be2 upstream.

This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.

* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
  and used in interrupt.

If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().

Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: mxs-auart: Fix baudrate calculation 2017-07-18T17:38:39+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2017-03-20T09:05:38+00:00 2a14908e68134912eeadc8f71690c52900abb371 commit a6040bc610554c66088fda3608ae5d6307c548e4 upstream. The reference manual for the i.MX28 recommends to calculate the divisor as divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer , so let's do this. For a typical setup of UARTCLK = 24 MHz and baud rate = 115200 this changes the divisor from 6666 to 6667 and so the actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to 115194.240 Bd (error ≅ 0.005 %). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit a6040bc610554c66088fda3608ae5d6307c548e4 upstream.

The reference manual for the i.MX28 recommends to calculate the divisor
as

	divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer

, so let's do this. For a typical setup of UARTCLK = 24 MHz and baud
rate = 115200 this changes the divisor from 6666 to 6667 and so the
actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to
115194.240 Bd (error ≅ 0.005 %).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: mxs-auart: fix baud rate range 2017-07-18T17:38:39+00:00 Stefan Wahren stefan.wahren@i2se.com 2015-08-11T11:46:01+00:00 c1b3678090794d3cd211de97f20fd19e5e29aee5 commit df57cf6a879502cd6e5559c1f2d6db12128e074f upstream. Currently mxs-auart doesn't care correctly about the baud rate divisor. According to reference manual the baud rate divisor must be between 0x000000EC and 0x003FFFC0. So calculate the possible baud rate range and use it for uart_get_baud_rate(). Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit df57cf6a879502cd6e5559c1f2d6db12128e074f upstream.

Currently mxs-auart doesn't care correctly about the baud rate divisor.
According to reference manual the baud rate divisor must be between
0x000000EC and 0x003FFFC0. So calculate the possible baud rate range
and use it for uart_get_baud_rate().

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
serial: 8250_pci: Add MKS Tenta SCOM-0800 and SCOM-0801 cards 2017-06-05T20:13:47+00:00 Ian Abbott abbotti@mev.co.uk 2017-02-03T20:25:00+00:00 9d61423fd84d61a27a1ac7f61e50c8a8fb8b403e commit 1c9c858e2ff8ae8024a3d75d2ed080063af43754 upstream. The MKS Instruments SCOM-0800 and SCOM-0801 cards (originally by Tenta Technologies) are 3U CompactPCI serial cards with 4 and 8 serial ports, respectively. The first 4 ports are implemented by an OX16PCI954 chip, and the second 4 ports are implemented by an OX16C954 chip on a local bus, bridged by the second PCI function of the OX16PCI954. The ports are jumper-selectable as RS-232 and RS-422/485, and the UARTs use a non-standard oscillator frequency of 20 MHz (base_baud = 1250000). Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1c9c858e2ff8ae8024a3d75d2ed080063af43754 upstream.

The MKS Instruments SCOM-0800 and SCOM-0801 cards (originally by Tenta
Technologies) are 3U CompactPCI serial cards with 4 and 8 serial ports,
respectively.  The first 4 ports are implemented by an OX16PCI954 chip,
and the second 4 ports are implemented by an OX16C954 chip on a local
bus, bridged by the second PCI function of the OX16PCI954.  The ports
are jumper-selectable as RS-232 and RS-422/485, and the UARTs use a
non-standard oscillator frequency of 20 MHz (base_baud = 1250000).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>