Commit 853a699739 ("serial: tegra: handle race condition on uart rx
side") attempted to fix a race condition between the RX end of
transmission interrupt and RX DMA completion callback. Despite this
fix there is still another case where these two paths can race and
result in duplicated data. The race condition is as follows:
1. DMA completion interrupt occurs and schedules tasklet to call DMA
callback.
2. DMA callback for the UART driver starts to execute. This will copy
the data from the DMA buffer and restart the DMA. This is done under
uart port spinlock.
3. During the callback, UART interrupt is raised for end of receive. The
UART ISR runs and waits to acquire port spinlock held by the DMA
callback.
4. DMA callback gives up spinlock after copying the data, but before
restarting DMA.
5. UART ISR acquires the spin lock and reads the same DMA buffer because
DMA has not been restarted yet.
The release of the spinlock during the DMA callback was introduced by
commit 9b88748b36 ("tty: serial: tegra: drop uart_port->lock before
calling tty_flip_buffer_push()") to fix a spinlock lock-up issue when
calling tty_flip_buffer_push(). However, since then commit a9c3f68f3c
("tty: Fix low_latency BUG") migrated tty_flip_buffer_push() to always
use a workqueue, allowing tty_flip_buffer_push() to be called from
within atomic sections. Therefore, we can remove the unlocking of the
spinlock from the DMA callback and UART ISR and this will ensure that
the race condition no longer occurs.
Reported-by: Christopher Freeman <cfreeman@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clearing UART_MCR_RTS or UART_MCR_XONANY is unnecessary; these bits
are never set in the shadow mcr. The RTS clear is especially confusing.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The same serial hardware is present on LS2080A which is arm64, and
LS1021A which is arm32, so don't limit the workaround to PPC.
Unlike PPC which uses arch/powerpc/kernel/legacy_serial.c, the ARM
targets use drivers/tty/serial/of_serial.c, so add the handle_irq
override check there as well.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to hardcode the MEN_Z135_MEM_SIZE. The MCB subsystem
already knowns the size which is located in the chameleon table.
MCB parse the chameleon table to get the resources of each IP and provide
the mcb_request_mem function to get those resources.
Use mcb_request_mem to get the resources. This function also takes care of
the memory region naming allocated by the driver for each of the instances.
Signed-off-by: Andreas Werner <andy@wernerandy.de>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Turning on KVM and LPAE support on top of a multi_v7_defconfig will
produce a compiler warning in the Atmel serial driver:
drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port':
drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
if ((void *)port->mapbase != ser->iomem_base)
^
Fix that by using the cast on the right hand side instead, as similar
code already does in other drivers.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We want the tty fixes and reverts in here as well so that people can
properly test and use it.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull scheduler fix from Thomas Gleixner:
"Fix a long standing state race in finish_task_switch()"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix TASK_DEAD race in finish_task_switch()
Pull perf fix from Thomas Glexiner:
"Fix build breakage on powerpc in perf tools"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix build break on powerpc due to sample_reg_masks
Pull maintainer email update from Thomas Gleixner:
"Change Matt Fleming's email address in the maintainers file"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
MAINTAINERS: Change Matt Fleming's email address
Pull irq fixes from Thomas Gleixner:
"Three trivial commits:
- Fix a kerneldoc regression
- Export handle_bad_irq to unbreak a driver in next
- Add an accessor for the of_node field so refactoring in next does
not depend on merge ordering"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqdomain: Add an accessor for the of_node field
genirq: Fix handle_bad_irq kerneldoc comment
genirq: Export handle_bad_irq
Pull SCSI fixes from James Bottomley:
"This is a set of three bug fixes, two of which are regressions from
recent updates (the 3ware one from 4.1 and the device handler fixes
from 4.2)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
3w-9xxx: don't unmap bounce buffered commands
scsi_dh: Use the correct module name when loading device handler
libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop
Pull md bugfix from Neil Brown:
"One bug fix for raid1/raid10.
Very careless bug earler in 4.3-rc, now fixed :-)"
* tag 'md/4.3-rc4-fix' of git://neil.brown.name/md:
crash in md-raid1 and md-raid10 due to incorrect list manipulation
Pull USB fixes from Greg KH:
"Here are some small USB and PHY fixes and quirk updates for 4.3-rc5.
Nothing major here, full details in the shortlog, and all of these
have been in linux-next for a while"
* tag 'usb-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: Add device quirk for Logitech PTZ cameras
USB: chaoskey read offset bug
USB: Add reset-resume quirk for two Plantronics usb headphones.
usb: renesas_usbhs: Add support for R-Car H3
usb: renesas_usbhs: fix build warning if 64-bit architecture
usb: gadget: bdc: fix memory leak
phy: berlin-sata: Fix module autoload for OF platform driver
phy: rockchip-usb: power down phy when rockchip phy probe
phy: qcom-ufs: fix build error when the component is built as a module
Pull tty/serial driver fixes from Greg KH:
"Here are a few bug fixes for the tty core that resolve reported
issues, and some serial driver fixes as well (including the
much-reported imx driver problem)
All of these have been in linux-next with no reported problems"
* tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
drivers/tty: require read access for controlling terminal
serial: 8250: add uart_config entry for PORT_RT2880
tty: fix data race on tty_buffer.commit
tty: fix data race in tty_buffer_flush
tty: fix data race in flush_to_ldisc
tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c
serial: atmel: fix error path of probe function
tty: don't leak cdev in tty_cdev_add()
Revert "serial: imx: remove unbalanced clk_prepare"
Pull staging fixes from Greg KH:
"Here are two tiny staging tree fixes for 4.3-rc5.
One fixes the broken speakup subsystem as reported by a user, and the
other removes an entry in the MAINTAINERS file for a developer that
doesn't want to be listed anymore"
* tag 'staging-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: speakup: fix speakup-r regression
MAINTAINERS: Remove myself as nvec co-maintainer
Pull char/misc driver fixes from Greg KH:
"Here are some small fixes for some misc drivers that resolve some
reported issues. All of these have been linux-next for a while"
* tag 'char-misc-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mcb: Fix error handling in mcb_pci_probe()
mei: hbm: fix error in state check logic
nvmem: sunxi: Check for memory allocation failure
nvmem: core: Fix memory leak in nvmem_cell_write
nvmem: core: Handle shift bits in-place if cell->nbits is non-zero
nvmem: core: fix the out-of-range leak in read/write()
Pull MIPS fixes from Ralf Baechle:
- MIPS didn't define the new ioremap_uc. Defined it as an alias for
ioremap_uncached.
- Replace workaround for MIPS16 build issue with a correct one.
* git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Define ioremap_uc
MIPS: UAPI: Ignore __arch_swab{16,32,64} when using MIPS16
Revert "MIPS: UAPI: Fix unrecognized opcode WSBH/DSBH/DSHD when using MIPS16."
Pull swiotlb fixlet from Konrad Rzeszutek Wilk:
"Enable the SWIOTLB under 32-bit PAE kernels.
Nowadays most distros enable this due to CONFIG_HYPERVISOR|XEN=y which
select SWIOTLB. But for those that are not interested in
virtualization and wanting to use 32-bit PAE kernels and wanting to
have working DMA operations - this configures it for them"
* 'stable/for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Enable it under x86 PAE
Leandro Awa writes:
"After switching to version 4.1.6, our parallelized and distributed
workflows now fail consistently with errors of the form:
T34: ./regex.c:39:22: error: config.h: No such file or directory
From our 'git bisect' testing, the following commit appears to be the
possible cause of the behavior we've been seeing: commit 766c4cbfacd8"
Al Viro says:
"What happens is that 766c4cbfac got the things subtly wrong.
We used to treat d_is_negative() after lookup_fast() as "fall with
ENOENT". That was wrong - checking ->d_flags outside of ->d_seq
protection is unreliable and failing with hard error on what should've
fallen back to non-RCU pathname resolution is a bug.
Unfortunately, we'd pulled the test too far up and ran afoul of
another kind of staleness. The dentry might have been absolutely
stable from the RCU point of view (and we might be on UP, etc), but
stale from the remote fs point of view. If ->d_revalidate() returns
"it's actually stale", dentry gets thrown away and the original code
wouldn't even have looked at its ->d_flags.
What we need is to check ->d_flags where 766c4cbfac does (prior to
->d_seq validation) but only use the result in cases where we do not
discard this dentry outright"
Reported-by: Leandro Awa <lawa@nvidia.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=104911
Fixes: 766c4cbfac ("namei: d_is_negative() should be checked...")
Tested-by: Leandro Awa <lawa@nvidia.com>
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull power management and ACPI fixes from Rafael Wysocki:
"These are four fixes for bugs in the devfreq and cpufreq subsystems,
including two regression fixes (one for a recent regression and one
for a problem introduced in 4.2).
Specifics:
- Two fixes for cpufreq regressions, an acpi-cpufreq driver one
introduced during the 4.2 cycle when we started to preserve cpufreq
directories for offline CPUs and a general one introduced recently
(Srinivas Pandruvada).
- Two devfreq fixes, one for a double kfree() in an error code path
and one for a confusing sysfs-related failure (Geliang Tang, Tobias
Jakobi)"
* tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: prevent lockup on reading scaling_available_frequencies
cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus
PM / devfreq: fix double kfree
PM / devfreq: Fix governor_store()
Pull strscpy powerpc fix from Chris Metcalf.
Fix powerpc big-endian build.
* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/powerpc: provide zero_bytemask() for big-endian
Pull sound fixes from Takashi Iwai:
"We see various small fixes, but nothing looks too scary, all are small
gentle bug fixes:
- Most of changes are for ASoC codecs: Realtek, SGTL5000, TAS2552,
TLV320, WM8962
- A couple of dwc and imx-ssi fixes
- Usual oneliner HD-audio quirks
- An old emux synth code fix"
* tag 'sound-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
MAINTAINERS: Remove wm97xx entry
ASoC: tas2552: fix dBscale-min declaration
ALSA: synth: Fix conflicting OSS device registration on AWE32
ALSA: hda - Disable power_save_node for IDT 92HD73xx chips
ALSA: hda - Apply SPDIF pin ctl to MacBookPro 12,1
ALSA: hda: Add dock support for ThinkPad T550
ASoC: dwc: fix dma stop transferring issue
ASoC: dwc: correct irq clear method
ASoC: tlv320aic3x: Prevent writing reserved registers on tlv320aic3104 CODECs
ASoC: rt5645: Correct the naming and setting of ADC Boost Volume Control
ASoC: sgtl5000: fix wrong register MIC_BIAS_VOLTAGE setup on probe
ASoC: wm8962: balance pm_runtime_enable
ASoC: imx-ssi: Fix DAI hardware signal inversions
ASoC: sgtl5000: fix error message output for MicBias voltage
ASoC: db1200: Fix DAI link format for db1300 and db1550
Pull clk fixes from Stephen Boyd:
"A Samsung driver fix and a handful of TI driver fixes"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: ti: dflt: fix enable_reg validity check
clk: ti: fix dual-registration of uart4_ick
clk: ti: clk-7xx: Remove hardwired ABE clock configuration
clk: samsung: fix cpu clock's flags checking
Jon Hunter
Peter Hurley
Scott Wood
Andreas Werner
Andre Przywara
Greg Kroah-Hartman
Linus Torvalds
Matt Fleming
Trond Myklebust