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 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
...
* '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>
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
Pull sparc updates from David Miller:
"Just a few small changes:
- Fix console naming inconsistency with hypervisor consoles, from
John Paul Adrian Glaubitz
- Fix userland compilation due to use of u_int, from Masahiro Yamada"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc64: Add missing newline at end of file
sparc: fix unknown type name u_int in uapi header
sparc: configs: Remove useless UEVENT_HELPER_PATH
sparc: Remove redundant copy of the LGPL-2.0
sunhv: Fix device naming inconsistency between sunhv_console and sunhv_reg
The lpuart of imx8ulp is basically the same as imx7ulp, but it
has new feature support based on imx7ulp, like it can assert a
DMA request on EOP(end-of-packet). imx8ulp lpuart use two clocks,
one is ipg bus clock that is used to access registers, the other
is baud clock that is used to transmit-receive data.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190704134007.2316-1-fugang.duan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When uart_flush_buffer() is called, the .flush_buffer() callback zeroes
the tx_dma_len field. This may race with the work queue function
handling transmit DMA requests:
1. If the buffer is flushed before the first DMA API call,
dmaengine_prep_slave_single() may be called with a zero length,
causing the DMA request to never complete, leading to messages
like:
rcar-dmac e7300000.dma-controller: Channel Address Error happen
and, with debug enabled:
sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126
and DMA timeouts.
2. If the buffer is flushed after the first DMA API call, but before
the second, dma_sync_single_for_device() may be called with a zero
length, causing the transmit data not to be flushed to RAM, and
leading to stale data being output.
Fix this by:
1. Letting sci_dma_tx_work_fn() return immediately if the transmit
buffer is empty,
2. Extending the critical section to cover all DMA preparational work,
so tx_dma_len stays consistent for all of it,
3. Using local copies of circ_buf.head and circ_buf.tail, to make sure
they match the actual operation above.
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds a flush of RX and TX FIFOs, and fixes some errors:
- adds RX FIFO flush in startup fonction
- removes the useless transmitter enabling in startup fonction
(e.g. receiver only, see Documentation/serial/driver)
- configures FIFO threshold before enabling it, rather than after
- flushes both TX and RX in set_termios function
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds the support of RX FIFO threshold in order to improve the RX FIFO
management.
This is done by enabling fifo threshold interrupt, instead of relying
on rx empty/fifo not full irq. That basically generates one irq/char
currently. With this patch:
- RXCFG is set to half fifo size (e.g. 16/2 = 8 data for a 16 data depth
FIFO)
- irq rate may be reduced by up to 1/RXCFG, e.g. 1 over 8 with current
RXCFG setting.
- Receiver timeout is used to gather chars when FIFO threshold isn't
reached.
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
