== Linus Walleij linusw ==
=== Highlights ===
* Finally sent out a patch for SPARSE_IRQ on the Nomadik
and ux500. Sadly it seems that to get a kernel that isn't screaming
at you, transitioning to sparse IRQ can not be done unless you
move over to irqdomains, all dynamic IRQ numbers and device
tree at the same time. This puzzled me for a long time.
* Started to drill into a RCU lockup regression that is still in the
v3.6-rc series, but I'm uncertain if it only affects ux500 or if
it's a generic problem. John Stultz has seen the same message.
* Helped Benjamin with pre-review of a patch to genalloc.
* First review of Lee's patch set for HREF/MOP500 device tree
support for the parts that I understand.
* Fixed a smallish regression on the ks8695 watchdog that
came as fallout from the timer patches.
* Reviewed and merged various GPIO patches.
* Reviewed and merged various pinctrl patches. Currently
the Marvell patch set is taking up a lot of bandwidth but
starting to look really nice.
* Attended an internal workshop on kernel architecture that
stole away some three working days or so, but hey, we get
to influence the ST-Ericsson internal kernel.
=== Plans ===
* Ongoing work on sparse IRQ for Nomadik and Ux500.
* Test the PL08x patches on the Ericsson Research
PB11MPCore and submit platform data for using
pl08x DMA on that platform.
* Look into other Ux500 stuff in need of mainlining...
using an internal tracking sheet for this.
* Look into regmap. Try something out, get to know it.
=== Issues ===
* N/A
Thanks,
Linus Walleij
Hi All,
I was trying booting 3.1.5 linaro kernel with wheezy debian filesystem on
pandaboard, but I found ethernet is not working.
On further check I found, there is no net interface under /sys/class/net/
except loopback. Though I have checked kernel config is having scm91x (and
scm911x) enabled.
I am really not sure about net driver details but I could not see these
drivers are getting probed at kernel boot.
Whereas, I have taken 3.2 kernel from kernel.org and it worked perfectly
fine and there is no change in defconfig file from 3.1.5.
I also observed the code structure for ethernet drivers are different
between 3.1.5 and 3.2 but driver files are same except
*ndo_set_rx_mode* has been implemented in 3.2 in place of *
ndo_set_multicast_list.*
any idea, about this problem? is it known???
Or is it something I am missing??
Thanks in advance
--
With Best Regards,
*Tirtha*
[image: Nico Nico animated GIF --]
Hi All,
I was trying booting 3.1.5 linaro kernel with wheezy debian filesystem on
pandaboard, but I found ethernet is not working.
On further check I found, there is no net interface under /sys/class/net/
except loopback. Though I have checked kernel config is having scm91x (and
scm911x) enabled.
I am really not sure about net driver details but I could not see these
drivers are getting probed at kernel boot.
Whereas, I have taken 3.2 kernel from kernel.org and it worked perfectly
fine and there is no change in defconfig file from 3.1.5.
I also observed the code structure for ethernet drivers are different
between 3.1.5 and 3.2 but driver files are same except
*ndo_set_rx_mode* has been implemented in 3.2 in place of *
ndo_set_multicast_list.*
any idea, about this problem? is it known???
Or is it something I am missing??
Thanks in advance
--
With Best Regards,
*Tirtha*
[image: Nico Nico animated GIF --]
Hi all,
Here is a new revision, mostly tty reworks. The new tty_port stuff is a
bliss: no more per-driver mutex, no more counting for open(),
well-separated initialization callbacks (I hope I got them right :-).
But since I now use a lot of new tty_port stuff, I had to rebase the
patch set on top of tty-next, so there's no point in cherry-picking
anymore.
So, in v6:
- Converted the NMI tty driver to use tty_port helpers, per Alan Cox's
suggestions;
- In uart's poll_init callback fixed a race, spotted by Alan;
- Use test_bit instead of touching port->flags directly;
These patches can be found in the following repo (based on tty-next):
git://git.infradead.org/users/cbou/linux-nmi-kdb.git master
Old changelogs and rationale for these patches can be found here:
v1-v5: http://lkml.org/lkml/2012/9/10/2
Thanks,
--
arch/arm/Kconfig | 19 ++
arch/arm/common/vic.c | 28 +++
arch/arm/include/asm/hardware/vic.h | 2 +
arch/arm/include/asm/kgdb.h | 8 +
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/entry-armv.S | 167 +------------
arch/arm/kernel/entry-header.S | 170 +++++++++++++
arch/arm/kernel/kgdb_fiq.c | 99 ++++++++
arch/arm/kernel/kgdb_fiq_entry.S | 87 +++++++
arch/arm/mach-versatile/Makefile | 1 +
arch/arm/mach-versatile/kgdb_fiq.c | 31 +++
drivers/tty/serial/Kconfig | 19 ++
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/amba-pl011.c | 66 ++++-
drivers/tty/serial/kgdb_nmi.c | 391 ++++++++++++++++++++++++++++++
drivers/tty/serial/kgdboc.c | 16 ++
drivers/tty/serial/serial_core.c | 32 +++
include/linux/kdb.h | 29 ++-
include/linux/kgdb.h | 34 +++
include/linux/serial_core.h | 2 +
include/linux/tty_driver.h | 1 +
kernel/debug/debug_core.c | 36 ++-
kernel/debug/kdb/kdb_main.c | 29 +++
23 files changed, 1076 insertions(+), 193 deletions(-)
Hi all,
There wasn't much feedback on v4, the only comment was from Brian
Swetland concerning async console (I explained how we deal with it).
It would be really great if the core functionality could make it into
v3.7. Which raises the question: if the patches are OK, who should take
them? They touch 3 subsystems: KGDB, TTY and ARM.
Taking the patches via -mm or TTY trees would be the easiest way as this
way we'll avoid having to deal with conflicts (see changelog*). But
merging via ARM or KDB will also work.
Russell, Jason, naively presuming that the ARM & KDB patches are OK,
would you be willing to ack ARM/KDB patches? Or, in case if it goes via
KDB or ARM tree, we'll need acks from Greg and Alan on tty patches...
Anyways, here goes the shiny v5:
- *I took two amba-pl1011 patches from Greg's tty tree. This is needed
to ease Stephen Rothwell's life in case if this goes into -next via
non-tty or non-mm tree.
The problem is that we now touch the same lines as tty tree, and
conflicts are not trivial. But by taking the two patches and rebasing
my work on top, we turn the conflicts into trivial ones.
- There were some concerns that '$3#33' might be not lengthy enough
(i.e., it's a bit shorter than '\nreboot\n'). Reading 2GB of
/dev/urandom couldn't find $3#33 sequence, but I made the magic phrase
configurable via kgdb_nmi.magic kernel command line option, just in
case.
These patches can be found in the following repo:
git://git.infradead.org/users/cbou/linux-nmi-kdb.git master
Boilerplate:
These patches introduce KGDB FIQ debugger support. The idea (and some
code, of course) comes from Google's FIQ debugger[2]. There are some
differences (mostly implementation details, feature-wise they're almost
equivalent, or can be made equivalent, if desired).
The FIQ debugger is a facility that can be used to debug situations when
the kernel stuck in uninterruptable sections, e.g. the kernel infinitely
loops or deadlocked in an interrupt or with interrupts disabled. On some
development boards there is even a special NMI button, which is very
useful for debugging weird kernel hangs.
And FIQ is basically an NMI, it has a higher priority than IRQs, and
upon IRQ exception FIQs are not disabled. It is still possible to
disable FIQs (as well as some "NMIs" on other architectures), but via
special means.
So, here FIQs and NMIs are synonyms, but in the code I use NMI term for
arch-independent code, and FIQs for ARM code.
A few years ago KDB wasn't yet ready for production, or even not
well-known, so originally Google implemented its own FIQ debugger that
included its own shell, ring-buffer, commands, dumping, backtracing
logic and whatnot. This is very much like PowerPC's xmon
(arch/powerpc/xmon), except that xmon was there for a decade, so it even
predates KDB.
Anyway, nowadays KGDB/KDB is the cross-platform debugger, and the only
feature that was missing is NMI handling. This is now fixed for ARM.
There are a few differences comparing to the original (Google's) FIQ
debugger:
- Doing stuff in FIQ context is dangerous, as there we are not allowed
to cause aborts or faults. In the original FIQ debugger there was a
"signal" software-induced interrupt, upon exit from FIQ it would fire,
and we would continue to execute "dangerous" commands from there.
In KGDB/KDB we don't use signal interrupts. We can do easier: set up a
breakpoint, continue, and you'll trap into KGDB again in a safe
context.
It works for most cases, but I can imagine cases when you can't set up
a breakpoint. For these cases we'd better introduce a KDB command
"exit_nmi", that will rise the SW IRQ, after which we're allowed to do
anything.
- KGDB/KDB FIQ debugger shell is synchronous. In Google's version you
could have a dedicated shell always running in the FIQ context, so
when you type something on a serial line, you won't actually cause any
debugging actions, FIQ would save the characters in its own buffer and
continue execution normally. But when you hit return key after the
command, then the command is executed.
In KGDB/KDB FIQ debugger it is different. Once you enter KGDB, the
kernel will stop until you instruct it to continue.
This might look as a drastic change, but it is not. There is actually
no difference whether you have sync or async shell, or at least I
couldn't find any use-case where this would matter at all. Anyways, it
is still possible to do async shell in KDB, just don't see any need
for this.
- Original FIQ debugger used a custom FIQ vector handling code, w/ a lot
of logic in it. In this approach I'm using the fact that FIQs are
basically IRQs, except that we there are a bit more registers banked,
and we can actually trap from the IRQ context.
But this all does not prevent us from using a simple jump-table based
approach as used in the generic ARM entry code. So, here I just reuse
the generic approach.
Note that I test the code on a modelled ARM machine (QEMU Versatile), so
there might be some issues on a real HW, but it works in QEMU tho. :-)
Assuming you have QEMU >= 1.1.0, you can easily play with the code using
ARM/versatile defconfig and command like this:
qemu-system-arm -nographic -machine versatilepb -kernel
linux/arch/arm/boot/zImage -append "console=ttyAMA0 kgdboc=ttyAMA0
kgdb_fiq.enable=1"
Thanks,
--
arch/arm/Kconfig | 19 ++
arch/arm/common/vic.c | 28 +++
arch/arm/include/asm/hardware/vic.h | 2 +
arch/arm/include/asm/kgdb.h | 8 +
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/entry-armv.S | 167 +-------------
arch/arm/kernel/entry-header.S | 170 +++++++++++++++
arch/arm/kernel/kgdb_fiq.c | 99 +++++++++
arch/arm/kernel/kgdb_fiq_entry.S | 87 ++++++++
arch/arm/mach-versatile/Makefile | 1 +
arch/arm/mach-versatile/kgdb_fiq.c | 31 +++
drivers/tty/serial/Kconfig | 19 ++
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/amba-pl010.c | 15 +-
drivers/tty/serial/amba-pl011.c | 106 +++++----
drivers/tty/serial/kgdb_nmi.c | 352 ++++++++++++++++++++++++++++++
drivers/tty/serial/kgdboc.c | 16 ++
drivers/tty/serial/serial_core.c | 30 +++
include/linux/kdb.h | 29 +--
include/linux/kgdb.h | 34 +++
include/linux/serial_core.h | 2 +
include/linux/tty_driver.h | 1 +
kernel/debug/debug_core.c | 36 ++-
kernel/debug/kdb/kdb_main.c | 29 +++
24 files changed, 1051 insertions(+), 232 deletions(-)
In v4:
- Implemented kgdb_nmi serial driver, it provides 'nmi_console' KDB
command. With the driver we can use our debugger port as a normal
console, except that we can always get back to the debugger using the
magic sequence. Note that I still somewhat reluctant to introduce
software-raised interrupts, as they're arch-specific and not always
possible. So today the driver uses a tasklet, it should be pretty
cheap: we're checking for the input on timer interrupts, but we don't
cause needless wakeups. The pro of this is that it works everywhere
(but arches still have an option to optimize things, of course);
- Two new patches added to propagate init_poll() callbacks from tty to
uart drivers. As a side-effect, a long-standing bug fixed in
amba-pl1011 driver;
- Dropped patch 'Get rid of .LCcralign local label';
- Some more fixes in SVC return path. Now it seems rock-solid;
In v3:
- Per Colin Cross suggestion, added a way to release a debug console for
normal use. This is done via 'disable_nmi' command (in the original
FIQ debugger it was 'console' command). For this I added a new
callback in the tty ops, and serial drivers have to provide a way to
clear its interrupts. The patch 'tty/serial/kgdboc: Add and wire up
clear_irqs callback' explains the concept in details.
- Made the debug entry prompt more shell-like;
- A new knocking mode '-1'. It disables the feature altogether, and thus
makes it possible to hook KDB entry to a dedicated button.
- The code was rebased on 'v3.5 + kdb kiosk'[1] patches;
In v2:
- Per Colin Cross' suggestion, we should not enter the debugger on any
received byte (this might be a problem when there's a noise on the
serial line). So there is now an additional patch that implements
"knocking" to the KDB (either via $3#33 command or return key, this is
configurable);
- Reworked {enable,select}_fiq/is_fiq callbacks, now multi-mach kernels
should not be a problem;
- For versatile machines there are run-time checks for proper UART port
(kernel will scream aloud if out of range port is specified);
- Added some __init annotations;
- Since not every architecture defines FIQ_START, we can't just blindly
select CONFIG_FIQ symbol. So ARCH_MIGHT_HAVE_FIQ introduced;
- Add !THUMB2_KERNEL dependency for KGDB_FIQ, we don't support Thumb2
kernels;
- New patch that is used to get rid of LCcralign label in alignment_trap
macro.
[1] https://lkml.org/lkml/2012/7/26/260
[2] Original Google's FIQ debugger, fiq_* files:
http://android.git.linaro.org/gitweb?p=kernel/common.git;a=tree;f=arch/arm/…
And board support as an example of using it:
http://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=commitdiff;h=461cb80c1…
=== Highlights ===
Get LTP-DDT Test Working in LAVA:
1.Investigation on LTP-DDT, how to build it, run it, configure it :
Completed
2.Get ltp-ddt running successfully on a snowball locally(Limited
Testcases): Completed
3.Create a wrapper for LTP-DDT in lava-test: Started
=== Plans ===
Add ltp-ddt to appropriate kernel and/or daily runs as needed.
Documentation for Driver test cases.
Thanks,
Appala
== Deepak Saxena <dsaxena> ==
=== Highlights ===
* Returned from two weeks of vacation, so not much to report here
=== Plans ===
* Catch up with all email
* Brainstorm with Jakub on kernel project management
* Roadmap card review with OPSCOM
* Start planning for Connect
* Usual 1:1's/meetings
=== Issues ===
=== Travel/Time Off ===
* Travelling to NYC for 1 week, Sept 22nd - 28th, will be working
half/three-fourth time.
(This may get cancelled)
* Cambridge, UK first week of October for AArch64 discussion/bring up
* Copenhagen Connect
=== omarrmz ===
* ARMv8t
- Compile aarch64 binutils. DONE
- Need to recompile the toolchain using the aarch64 binutils. DONE
- Compile the aarch64 kernel with aarch64 toolchain: DONE.
- Plain config generated through menuconfig.
* Mailbox runtime OFF mode: DONE.
- Tested on OMAP3 and OMAP4
- Needs to be submitted to LO.
* Consolidate iommu changes into original series: IN PROGRESS.
* Get some time to do an omap mailbox cleanup: NO UPDATE.
- Low priority.
* Review patches from Laurent on tidspbridge: IN PROGRESS.
- Reviewed 4 fo 13 patches so far.
- Review a separate bug he is reporting.
=== Plans ===
* Continue to ping Paul for my reset patches in the mailing list.
* Keep on looking at aarch64 patches.
Regards,
Omar
=== Highlights ===
* Sent v4 generic cpufreq driver cpufreq-cpu0. Rafael queued it for
3.7 for linux-pm tree.
* Running into a sleep-in-atomic warning with cpufreq-cpu0 driver.
It turns out that smp_twd driver calls clk_get_rate which holds
a mutex in interrupt context. Dug and sent out a patch from Mike
which could be a fix for review.
* Mike applied patch of_clk_src_onecell_get() which is required by
imx/mxs DT clk lookup.
* Sent a patch on kernel/sys.c to call disable_nonboot_cpus in
kernel_restart, which can help one reboot issue seen on imx6q.
Andrew had it applied on -mm tree.
* Reviewed patch series "Add device tree support for on-chip SRAM"
from Philipp Zabel.
* Reviewed a series adding device tree support for imx pwm driver
from Sascha.
* Reviewed a series from Dong, adding syscon driver based on regmap
for general registers access.
--
Regards,
Shawn
=== Highlights ===
* LWN covered my Android Upstreaming Summary here:
https://lwn.net/Articles/514901/
* Implemented byte-range management for volatile ranges.
* After talking with Thomas last week, I took a first pass at
implementing refined-jiffies, which should allow CLOCK_TICK_RATE to be
managed dynamically rather then statically. This helps the unified
zImage work.
* Generated a patch implementing Tixy's suggested fix for the evdev
issue he was seeing. Sent it to Rafael for review and then submitted it
to lkml. Its queued for 3.7
* Got feedback from Mozilla developers, clarifying what their needs are
with respect to the volatile ranges patch
* Got weekly Android upstreaming email going again
* Replied to questions related to my Android Upstreaming Summary
* Followed up on time patches that should be backported to -stable.
Generated patch queues for each of the -stable trees.
* Did some further work prepping time changes for 3.7
* Investigated time regression in 3.6
* Replied to clock TAI question on the ptp list.
=== Plans ===
* Make first pass at sending SIGBUS on accessing purged volatile pages
* Finish testing of refined jiffies and send patches out
* Finish testing -stable backports, and send patches out
=== Issues ===
* NA
