For many years omap variants have been setting the runtime PM
autosuspend delay to -1 to prevent unsafe policy with lossy first
character on wake-up. The user must specifically enable the timeout
for UARTs if desired.
We must not enable the workaround for serdev devices though. It leads
into UARTs not idling if no serdev devices are loaded and there is no
sysfs entry to configure the UART in that case. And this means that
my PM may not work unless the serdev modules are loaded.
We can detect a serdev device being configured based on a dts child
node, and we can simply skip the workround in that case. And the
serdev driver can idle the port during runtime when suitable if an
out-of-band wake-up GPIO line exists for example.
Let's also add some comments to the workaround while at it.
Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20190723115400.46432-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lock down TIOCSSERIAL as that can be used to change the ioport and irq
settings on a serial port. This only appears to be an issue for the serial
drivers that use the core serial code. All other drivers seem to either
ignore attempts to change port/irq or give an error.
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
After commit ddde3c18b7 ("vt: More locking checks") kdb / kgdb has
become useless because my console is filled with spews of:
WARNING: CPU: 0 PID: 0 at .../drivers/tty/vt/vt.c:3846 con_is_visible+0x50/0x74
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc1+ #48
Hardware name: Rockchip (Device Tree)
Backtrace:
[<c020ce9c>] (dump_backtrace) from [<c020d188>] (show_stack+0x20/0x24)
[<c020d168>] (show_stack) from [<c0a8fc14>] (dump_stack+0xb0/0xd0)
[<c0a8fb64>] (dump_stack) from [<c0232c58>] (__warn+0xec/0x11c)
[<c0232b6c>] (__warn) from [<c0232dc4>] (warn_slowpath_null+0x4c/0x58)
[<c0232d78>] (warn_slowpath_null) from [<c06338a0>] (con_is_visible+0x50/0x74)
[<c0633850>] (con_is_visible) from [<c0634078>] (con_scroll+0x108/0x1ac)
[<c0633f70>] (con_scroll) from [<c0634160>] (lf+0x44/0x88)
[<c063411c>] (lf) from [<c06363ec>] (vt_console_print+0x1a4/0x2bc)
[<c0636248>] (vt_console_print) from [<c02f628c>] (vkdb_printf+0x420/0x8a4)
[<c02f5e6c>] (vkdb_printf) from [<c02f6754>] (kdb_printf+0x44/0x60)
[<c02f6714>] (kdb_printf) from [<c02fa6f4>] (kdb_main_loop+0xf4/0x6e0)
[<c02fa600>] (kdb_main_loop) from [<c02fd5f0>] (kdb_stub+0x268/0x398)
[<c02fd388>] (kdb_stub) from [<c02f3ba0>] (kgdb_cpu_enter+0x1f8/0x674)
[<c02f39a8>] (kgdb_cpu_enter) from [<c02f4330>] (kgdb_handle_exception+0x1c4/0x1fc)
[<c02f416c>] (kgdb_handle_exception) from [<c0210fe0>] (kgdb_compiled_brk_fn+0x30/0x3c)
[<c0210fb0>] (kgdb_compiled_brk_fn) from [<c020d7ac>] (do_undefinstr+0x180/0x1a0)
[<c020d62c>] (do_undefinstr) from [<c0201b44>] (__und_svc_finish+0x0/0x3c)
...
[<c02f3224>] (kgdb_breakpoint) from [<c02f3310>] (sysrq_handle_dbg+0x58/0x6c)
[<c02f32b8>] (sysrq_handle_dbg) from [<c062abf0>] (__handle_sysrq+0xac/0x154)
Let's disable this warning when we're in kgdb to avoid the spew. The
whole system is stopped when we're in kgdb so we can't exactly wait
for someone else to drop the lock. Presumably the best we can do is
to disable the warning and hope for the best.
Fixes: ddde3c18b7 ("vt: More locking checks")
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20190725183551.169208-1-dianders@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty fixes from Greg KH:
"Here are two tty/vt fixes:
- delete the netx-serial driver as the arch has been removed, no need
to keep the serial driver for it around either.
- vt console_lock fix to resolve a reported noisy warning at runtime
Both of these have been in linux-next with no reported issues"
* tag 'tty-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
vt: Grab console_lock around con_is_bound in show_bind
tty: serial: netx: Delete driver
Pull locking fixes from Thomas Gleixner:
"A set of locking fixes:
- Address the fallout of the rwsem rework. Missing ACQUIREs and a
sanity check to prevent a use-after-free
- Add missing checks for unitialized mutexes when mutex debugging is
enabled.
- Remove the bogus code in the generic SMP variant of
arch_futex_atomic_op_inuser()
- Fixup the #ifdeffery in lockdep to prevent compile warnings"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/mutex: Test for initialized mutex
locking/lockdep: Clean up #ifdef checks
locking/lockdep: Hide unused 'class' variable
locking/rwsem: Add ACQUIRE comments
tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
locking/rwsem: Don't call owner_on_cpu() on read-owner
futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
While reviewing rwsem down_slowpath, Will noticed ldsem had a copy of
a bug we just found for rwsem.
X = 0;
CPU0 CPU1
rwsem_down_read()
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
X = 1;
rwsem_up_write();
rwsem_mark_wake()
atomic_long_add(adjustment, &sem->count);
smp_store_release(&waiter->task, NULL);
if (!waiter.task)
break;
...
}
r = X;
Allows 'r == 0'.
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 4898e640ca ("tty: Add timed, writer-prioritized rw semaphore")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull ARM SoC platform updates from Olof Johansson:
"SoC platform changes. Main theme this merge window:
- The Netx platform (Netx 100/500) platform is removed by Linus
Walleij-- the SoC doesn't have active maintainers with hardware,
and in discussions with the vendor the agreement was that it's OK
to remove.
- Russell King has a series of patches that cleans up and refactors
SA1101 and RiscPC support"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (47 commits)
ARM: stm32: use "depends on" instead of "if" after prompt
ARM: sa1100: convert to common clock framework
ARM: exynos: Cleanup cppcheck shifting warning
ARM: pxa/lubbock: remove lubbock_set_misc_wr() from global view
ARM: exynos: Only build MCPM support if used
arm: add missing include platform-data/atmel.h
ARM: davinci: Use GPIO lookup table for DA850 LEDs
ARM: OMAP2: drop explicit assembler architecture
ARM: use arch_extension directive instead of arch argument
ARM: imx: Switch imx7d to imx-cpufreq-dt for speed-grading
ARM: bcm: Enable PINCTRL for ARCH_BRCMSTB
ARM: bcm: Enable ARCH_HAS_RESET_CONTROLLER for ARCH_BRCMSTB
ARM: riscpc: enable chained scatterlist support
ARM: riscpc: reduce IRQ handling code
ARM: riscpc: move RiscPC assembly files from arch/arm/lib to mach-rpc
ARM: riscpc: parse video information from tagged list
ARM: riscpc: add ecard quirk for Atomwide 3port serial card
MAINTAINERS: mvebu: Add git entry
soc: ti: pm33xx: Add a print while entering RTC only mode with DDR in self-refresh
ARM: OMAP2+: Make some variables static
...
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert docs to ReST and add them to the arch-specific
book.
The conversion here was trivial, as almost every file there
was already using an elegant format close to ReST standard.
The changes were mostly to mark literal blocks and add a few
missing section title identifiers.
One note with regards to "--": on Sphinx, this can't be used
to identify a list, as it will format it badly. This can be
used, however, to identify a long hyphen - and "---" is an
even longer one.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> # cxl
* 'for-arm-soc' of git://git.armlinux.org.uk/~rmk/linux-arm: (21 commits)
ARM: sa1100: convert to common clock framework
ARM: riscpc: enable chained scatterlist support
ARM: riscpc: reduce IRQ handling code
ARM: riscpc: move RiscPC assembly files from arch/arm/lib to mach-rpc
ARM: riscpc: parse video information from tagged list
ARM: riscpc: add ecard quirk for Atomwide 3port serial card
ARM: sa1100/neponset: convert serial to use gpiod APIs
ARM: sa1100/hackkit: remove empty serial mctrl functions
ARM: sa1100/badge4: remove commented out modem control initialisers
ARM: sa1100/h3xxx: convert serial to gpiod APIs
ARM: sa1100/assabet: convert serial to gpiod APIs
serial: sa1100: add note about modem control signals
serial: sa1100: add support for mctrl gpios
ARM: riscpc: dma: use __iomem pointers for writing DMA
ARM: riscpc: dma: improve address/length writing
ARM: riscpc: dma: make state a local variable
ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage
ARM: riscpc: fix DMA
ARM: riscpc: fix ecard printing
ARM: riscpc: fix lack of keyboard interrupts after irq conversion
...
Signed-off-by: Olof Johansson <olof@lixom.net>
There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.
Move them to their right place.
Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Converts ARM the text files to ReST, preparing them to be an
architecture book.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
Convert this small file to ReST in preparation for adding it to
the driver-api book.
While this is not part of the driver-api book, mark it as
:orphan:, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
