linux-stable.git/drivers/tty/serial, branch v3.4

tty/serial/pmac_zilog: Fix "nobody cared" IRQ message

2012-04-30T00:59:58+00:00

Following commit a79dd5a titled "tty/serial/pmac_zilog: Fix suspend & resume",
my Powerbook G4 Titanium showed the following stack dump:

[   36.878225] irq 23: nobody cared (try booting with the "irqpoll" option)
[   36.878251] Call Trace:
[   36.878291] [dfff3f00] [c000984c] show_stack+0x7c/0x194 (unreliable)
[   36.878322] [dfff3f40] [c00a6868] __report_bad_irq+0x44/0xf4
[   36.878339] [dfff3f60] [c00a6b04] note_interrupt+0x1ec/0x2ac
[   36.878356] [dfff3f80] [c00a48d0] handle_irq_event_percpu+0x250/0x2b8
[   36.878372] [dfff3fd0] [c00a496c] handle_irq_event+0x34/0x54
[   36.878389] [dfff3fe0] [c00a753c] handle_fasteoi_irq+0xb4/0x124
[   36.878412] [dfff3ff0] [c000f5bc] call_handle_irq+0x18/0x28
[   36.878428] [deef1f10] [c000719c] do_IRQ+0x114/0x1cc
[   36.878446] [deef1f40] [c0015868] ret_from_except+0x0/0x1c
[   36.878484] --- Exception: 501 at 0xf497610
[   36.878489]     LR = 0xfdc3dd0
[   36.878497] handlers:
[   36.878510] [] pmz_interrupt
[   36.878520] Disabling IRQ #23

From an E-mail exchange about this problem, Andreas Schwab noticed a typo
that resulted in the wrong condition being tested.

The patch also corrects 2 typos that incorrectly report why an error branch
is being taken.

Signed-off-by: Larry Finger 
Signed-off-by: Benjamin Herrenschmidt

pch_uart: Fix dma channel unallocated issue

2012-04-18T22:19:50+00:00

This driver anticipates pch_uart_verify_port() is not called
during installation.
However, actually pch_uart_verify_port() is called during
installation.
As a result, memory access violation occurs like below.

0. initial value: use_dma=0
1. starup()
    - dma channel is not allocated because use_dma=0
2. pch_uart_verify_port()
    - Set use_dma=1
3. UART processing acts DMA mode because use_dma=1
     - memory access violation occurs!

This patch fixes the issue.

Solution:
Whenever pch_uart_verify_port() is called and then
dma channel is not allocated, the channel should be allocated.

Signed-off-by: Tomoya MORINAGA 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

ARM: clps711x: serial driver hungs are a result of call disable_irq within ISR

2012-04-18T22:19:50+00:00

Since 2.6.30-rc1 clps711x serial driver hungs system. This is a result
of call disable_irq from ISR. synchronize_irq waits for end of interrupt
and goes to infinite loop. This patch fix this problem.

Signed-off-by: Alexander Shiyan 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2012-04-12T22:36:33+00:00

Pull tty and serial fixes from Greg KH:
 "Here are some tty and serial fixes for 3.4-rc2.

  Most important here is the pl011 fix, which has been reported by about
  100 different people, which means more people use it than I expected
  :)

  There are also some 8250 driver reverts due to some problems reported
  by them.  And other minor fixes as well.

  Signed-off-by: Greg Kroah-Hartman "

* tag 'tty-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  pch_uart: Add Kontron COMe-mTT10 uart clock quirk
  pch_uart: Fix MSI setting issue
  serial/8250_pci: add a "force background timer" flag and use it for the "kt" serial port
  Revert "serial/8250_pci: setup-quirk workaround for the kt serial controller"
  Revert "serial/8250_pci: init-quirk msi support for kt serial controller"
  tty/serial/omap: console can only be built-in
  serial: samsung: fix omission initialize ulcon in reset port fn()
  printk(): add KERN_CONT where needed in hpet and vt code
  tty/serial: atmel_serial: fix RS485 half-duplex problem
  tty: serial: altera_uart: Check for NULL platform_data in probe.
  isdn/gigaset: use gig_dbg() for debugging output
  omap-serial: Fix the error handling in the omap_serial probe
  serial: PL011: move interrupt clearing

pch_uart: Add Kontron COMe-mTT10 uart clock quirk

2012-04-09T17:58:41+00:00

Add UART clock quirk for the Kontron COMe-mTT10 module.

The board has previously been called nanoETXexpress-TT, therefore this
is also checked.

As suggested by Darren Hart the comparison in this patch version is
placed after the FRI2 checks to ensure it will also work with possible
upcoming changes to the FRI2 firmware.

This patch follows the patchset submitted by Darren Hart at
commit a46f5533ecfc7bbdd646d84fdab8656031a715c6.

Signed-off-by: Michael Brunner 
Acked-by: Darren Hart 
Signed-off-by: Greg Kroah-Hartman

pch_uart: Fix MSI setting issue

2012-04-09T17:43:26+00:00

The following patch (MSI setting) is not enough.

commit e463595fd9c752fa4bf06b47df93ef9ade3c7cf0
Author: Alexander Stein 
Date:   Mon Jul 4 08:58:31 2011 +0200

    pch_uart: Add MSI support

    Signed-off-by: Alexander Stein 
    Signed-off-by: Greg Kroah-Hartman 

To enable MSI mode, PCI bus-mastering must be enabled.
This patch enables the setting.

cc: Alexander Stein 
Signed-off-by: Tomoya MORINAGA 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial/8250_pci: add a "force background timer" flag and use it for the "kt" serial port

2012-04-09T17:38:30+00:00

Workaround dropped notifications in the iir register.  Register reads
coincident with new interrupt notifications sometimes result in this
device clearing the interrupt event without reporting it in the read
data.

The serial core already has a heuristic for determining when a device
has an untrustworthy iir register.  In this case when we apriori know
that the iir is faulty use a flag (UPF_BUG_THRE) to bypass the test and
force usage of the background timer.

[stable: 3.3.x]
Acked-by: Alan Cox 
Cc: stable 
Reported-by: Nhan H Mai 
Reported-by: Sudhakar Mamillapalli 
Tested-by: Nhan H Mai 
Tested-by: Sudhakar Mamillapalli 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

Revert "serial/8250_pci: setup-quirk workaround for the kt serial controller"

2012-04-09T17:34:52+00:00

This reverts commit 448ac154c957c4580531fa0c8f2045816fe2f0e7.

The semantic of UPF_IIR_ONCE is only guaranteed to workaround the race
condition in the kt serial's iir register if the only source of
interrupts is THRE (fifo-empty) events.  An modem status event at the
wrong time can again cause an iir read to drop the 'empty' status
leading to a hang.  So, revert this in preparation for using the
existing "I don't trust my iir register" workaround in the 8250 core
(UART_BUG_THRE).

[stable: 3.3.x]
Cc: stable 
Acked-by: Alan Cox 
Cc: Sudhakar Mamillapalli 
Reported-by: Nhan H Mai 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

Revert "serial/8250_pci: init-quirk msi support for kt serial controller"

2012-04-09T17:34:16+00:00

This reverts commit e86ff4a63c9fdd875ba8492577cd1ad2252f525c.

This tried to enforce the semantics of one interrupt per iir read of the
THRE (transmit-hold empty) status, but events from other sources
(particularly modem status) defeat this guarantee.

This change also broke 8250_pci suspend/resume support as
pciserial_resume_ports() re-runs .init() quirks, but does not run
.exit() quirks in pciserial_suspend_ports() leading to reports like:

  sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:16.3/msi_irqs'

...and a subsequent crash.  The mismatch of init/exit at suspend/resume
seems like a bug in its own right.

[stable: 3.3.x]
Cc: stable 
Acked-by: Alan Cox 
Cc: Sudhakar Mamillapalli 
Reported-by: Nhan H Mai 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

tty/serial/omap: console can only be built-in

2012-04-09T17:34:16+00:00

When the omap serial driver is built as a module, we must
not allow the console driver to be selected, because consoles
can not be loadable modules.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Mathieu Poirier 
Acked-by: Govindraj.R 
Signed-off-by: Greg Kroah-Hartman