user/sven/linux.git/drivers, branch v3.12.19

tty: Fix low_latency BUG

2014-05-05T12:24:38Z

commit a9c3f68f3cd8d55f809fbdb0c138ed061ea1bd25 upstream. The user-settable knob, low_latency, has been the source of several BUG reports which stem from flush_to_ldisc() running in interrupt context. Since 3.12, which added several sleeping locks (termios_rwsem and buf->lock) to the input processing path, the frequency of these BUG reports has increased. Note that changes in 3.12 did not introduce this regression; sleeping locks were first added to the input processing path with the removal of the BKL from N_TTY in commit a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc, 'n_tty: Fix loss of echoed characters and remove bkl from n_tty' and later in commit 38db89799bdf11625a831c5af33938dcb11908b6, 'tty: throttling race fix'. Since those changes, executing flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe. However, since most devices do not validate if the low_latency setting is appropriate for the context (process or interrupt) in which they receive data, some reports are due to misconfiguration. Further, serial dma devices for which dma fails, resort to interrupt receiving as a backup without resetting low_latency. Historically, low_latency was used to force wake-up the reading process rather than wait for the next scheduler tick. The effect was to trim multiple milliseconds of latency from when the process would receive new data. Recent tests [1] have shown that the reading process now receives data with only 10's of microseconds latency without low_latency set. Remove the low_latency rx steering from tty_flip_buffer_push(); however, leave the knob as an optional hint to drivers that can tune their rx fifos and such like. Cleanup stale code comments regarding low_latency. [1] https://lkml.org/lkml/2014/2/20/434 "Yay.. thats an annoying historical pain in the butt gone." -- Alan Cox Reported-by: Beat Bolli Reported-by: Pavel Roskin Acked-by: David Sterba Cc: Grant Edwards Cc: Stanislaw Gruszka Cc: Hal Murray Signed-off-by: Peter Hurley Signed-off-by: Alan Cox Signed-off-by: Jiri Slaby

tty: Set correct tty name in 'active' sysfs attribute

2014-05-05T12:24:37Z

commit 723abd87f6e536f1353c8f64f621520bc29523a3 upstream. The 'active' sysfs attribute should refer to the currently active tty devices the console is running on, not the currently active console. The console structure doesn't refer to any device in sysfs, only the tty the console is running on has. So we need to print out the tty names in 'active', not the console names. There is one special-case, which is tty0. If the console is directed to it, we want 'tty0' to show up in the file, so user-space knows that the messages get forwarded to the active VT. The ->device() callback would resolve tty0, though. Hence, treat it special and don't call into the VT layer to resolve it (plymouth is known to depend on it). Cc: Lennart Poettering Cc: Kay Sievers Cc: Jiri Slaby Signed-off-by: Werner Fink Signed-off-by: Hannes Reinecke Signed-off-by: David Herrmann Signed-off-by: Jiri Slaby

staging: comedi: 8255_pci: initialize MITE data window

2014-05-05T12:24:37Z

commit 268d1e799663b795cba15c64f5d29407786a9dd4 upstream. According to National Instruments' PCI-DIO-96/PXI-6508/PCI-6503 User Manual, the physical address in PCI BAR1 needs to be OR'ed with 0x80 and written to register offset 0xC0 in the "MITE" registers (BAR0). Do so during initialization of the National Instruments boards handled by the "8255_pci" driver. The boards were previously handled by the "ni_pcidio" driver, where the initialization was done by `mite_setup()` in the "mite" module. The "mite" module comes with too much extra baggage for the "8255_pci" driver to deal with so use a local, simpler initialization function. Signed-off-by: Ian Abbott Signed-off-by: Jiri Slaby

ACPI / button: Add ACPI Button event via netlink routine

2014-05-05T12:24:36Z

commit 0bf6368ee8f25826d0645c0f7a4f17c8845356a4 upstream. Commit 1696d9d (ACPI: Remove the old /proc/acpi/event interface) removed ACPI Button event which originally was sent to userspace via /proc/acpi/event. This caused ACPI shutdown regression on gentoo in VirtualBox. Now ACPI events are sent to userspace via netlink, so add ACPI Button event back via netlink routine. References: https://bugzilla.kernel.org/show_bug.cgi?id=71721 Reported-and-tested-by: Richard Musil Signed-off-by: Lan Tianyu Signed-off-by: Rafael J. Wysocki Signed-off-by: Jiri Slaby

PCI: designware: Fix iATU programming for cfg1, io and mem viewport

2014-05-05T12:24:35Z

commit 017fcdc30cdae18c0946eef1ece1f14b4c7897ba upstream. This patch corrects iATU programming for cfg1, io and mem viewport. Enable ATU only after configuring it. Signed-off-by: Mohit Kumar Signed-off-by: Ajay Khandelwal Signed-off-by: Bjorn Helgaas Acked-by: Jingoo Han Signed-off-by: Jiri Slaby

PCI: designware: Fix RC BAR to be single 64-bit non-prefetchable memory BAR

2014-05-05T12:24:35Z

commit dbffdd6862e67d60703f2df66c558bf448f81d6e upstream. The Synopsys PCIe core provides one pair of 32-bit BARs (BAR 0 and BAR 1). The BARs can be configured as follows: - One 64-bit BAR: BARs 0 and 1 are combined to form a single 64-bit BAR - Two 32-bit BARs: BARs 0 and 1 are two independent 32-bit BARs This patch corrects 64-bit, non-prefetchable memory BAR configuration implemented in dw driver. Signed-off-by: Mohit Kumar Signed-off-by: Bjorn Helgaas Cc: Pratyush Anand Cc: Jingoo Han Cc: Arnd Bergmann Signed-off-by: Jiri Slaby

ACPI / sleep: remove panic in case hardware has changed after S4

2014-05-05T12:21:49Z

commit 5c551e624abba6782034edd5b9eb58ac6f146b38 upstream. Some BIOSes change hardware based on the state of a laptop's lid. If the lid is closed, the touchpad is disabled and the checksum changes. Windows 8 no longer aborts resume if the checksum has changed. Signed-off-by: Oliver Neukum [rjw: Use pr_crit() for the message and don't break the string] Signed-off-by: Rafael J. Wysocki Signed-off-by: Jiri Slaby

ipmi: Fix a race restarting the timer

2014-05-05T11:39:23Z

commit 48e8ac2979920ffa39117e2d725afa3a749bfe8d upstream. With recent changes it is possible for the timer handler to detect an idle interface and not start the timer, but the thread to start an operation at the same time. The thread will not start the timer in that instance, resulting in the timer not running. Instead, move all timer operations under the lock and start the timer in the thread if it detect non-idle and the timer is not already running. Moving under locks allows the last timeout to be set in both the thread and the timer. 'Timer is not running' means that the timer is not pending and smi_timeout() is not running. So we need a flag to detect this correctly. Also fix a few other timeout bugs: setting the last timeout when the interrupt has to be disabled and the timer started, and setting the last timeout in check_start_timer_thread possibly racing with the timer Signed-off-by: Corey Minyard Signed-off-by: Bodo Stroesser Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby

virtio_balloon: don't softlockup on huge balloon changes.

2014-05-05T11:38:19Z

commit 1f74ef0f2d7d692fcd615621e0e734c3e7771413 upstream. When adding or removing 100G from a balloon: BUG: soft lockup - CPU#0 stuck for 22s! [vballoon:367] We have a wait_event_interruptible(), but the condition is always true (more ballooning to do) so we don't ever sleep. We also have a wait_event() for the host to ack, but that is also always true as QEMU is synchronous for balloon operations. Reported-by: Gopesh Kumar Chaudhary Cc: stable@kernel.org Signed-off-by: Rusty Russell Signed-off-by: Jiri Slaby

amd64_edac: Fix logic to determine channel for F15 M30h processors

2014-05-05T11:26:04Z

commit 9d0e8d8348d54d60005c6c938b87b94648005d1c upstream. Update current channel selection logic to include F15h, M30h memory controllers. Refer F15 M30h BKDG D18F2x110[7:6] (DRAM Controller Select Low) (Link:http://support.amd.com/TechDocs/49125_15h_Models_30h-3Fh_BKDG.pdf) Signed-off-by: Aravind Gopalakrishnan Link: http://lkml.kernel.org/r/1390338216-3873-1-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov Signed-off-by: Jiri Slaby