commit fb78b81142 provide a workaround for
kernel panic, but bring potential deadlock risk. that is in
sirfsoc_rx_tmo_process_tl while enter into sirfsoc_uart_pio_rx_chars
cpu hold uart_port->lock, if uart interrupt comes cpu enter into
sirfsoc_uart_isr and deadlock occurs in getting uart_port->lock.
the patch replace spin_lock version to spin_lock_irq* version to avoid
spinlock dead lock issue. let function tty_flip_buffer_push in tasklet
outof spin_lock_irq* protect area to avoid add the pair of spin_lock and
spin_unlock for tty_flip_buffer_push.
BTW drop self defined unused spinlock protect of tx_lock/rx_lock.
56274.220464] BUG: spinlock lockup suspected on CPU#0, swapper/0/0
[56274.223648] lock: 0xc05d9db0, .magic: dead4ead, .owner: swapper/0/0,
.owner_cpu: 0
[56274.231278] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G
O 3.10.35 #1
[56274.238241] [<c0015530>] (unwind_backtrace+0x0/0xf4) from
[<c00120d8>] (show_stack+0x10/0x14)
[56274.246742] [<c00120d8>] (show_stack+0x10/0x14) from
[<c01b11b0>] (do_raw_spin_lock+0x110/0x184)
[56274.255501] [<c01b11b0>] (do_raw_spin_lock+0x110/0x184) from
[<c02124c8>] (sirfsoc_uart_isr+0x20/0x42c)
[56274.264874] [<c02124c8>] (sirfsoc_uart_isr+0x20/0x42c) from
[<c0075790>] (handle_irq_event_percpu+0x54/0x17c)
[56274.274758] [<c0075790>] (handle_irq_event_percpu+0x54/0x17c)
from [<c00758f4>] (handle_irq_event+0x3c/0x5c)
[56274.284561] [<c00758f4>] (handle_irq_event+0x3c/0x5c) from
[<c0077fa0>] (handle_level_irq+0x98/0xfc)
[56274.293670] [<c0077fa0>] (handle_level_irq+0x98/0xfc) from
[<c0074f44>] (generic_handle_irq+0x2c/0x3c)
[56274.302952] [<c0074f44>] (generic_handle_irq+0x2c/0x3c) from
[<c000ef80>] (handle_IRQ+0x40/0x90)
[56274.311706] [<c000ef80>] (handle_IRQ+0x40/0x90) from
[<c000dc80>] (__irq_svc+0x40/0x70)
[56274.319697] [<c000dc80>] (__irq_svc+0x40/0x70) from
[<c038113c>] (_raw_spin_unlock_irqrestore+0x10/0x48)
[56274.329158] [<c038113c>]
(_raw_spin_unlock_irqrestore+0x10/0x48) from [<c0200034>]
(tty_port_tty_get+0x58/0x90)
[56274.339213] [<c0200034>] (tty_port_tty_get+0x58/0x90) from
[<c0212008>] (sirfsoc_uart_pio_rx_chars+0x1c/0xc8)
[56274.349097] [<c0212008>]
(sirfsoc_uart_pio_rx_chars+0x1c/0xc8) from [<c0212ef8>]
(sirfsoc_rx_tmo_process_tl+0xe4/0x1fc)
[56274.359853] [<c0212ef8>]
(sirfsoc_rx_tmo_process_tl+0xe4/0x1fc) from [<c0027c04>]
(tasklet_action+0x84/0x114)
[56274.369739] [<c0027c04>] (tasklet_action+0x84/0x114) from
[<c0027db4>] (__do_softirq+0x120/0x200)
[56274.378585] [<c0027db4>] (__do_softirq+0x120/0x200) from
[<c0027f44>] (do_softirq+0x54/0x5c)
[56274.386998] [<c0027f44>] (do_softirq+0x54/0x5c) from
[<c00281ec>] (irq_exit+0x9c/0xd0)
[56274.394899] [<c00281ec>] (irq_exit+0x9c/0xd0) from
[<c000ef84>] (handle_IRQ+0x44/0x90)
[56274.402790] [<c000ef84>] (handle_IRQ+0x44/0x90) from
[<c000dc80>] (__irq_svc+0x40/0x70)
[56274.410774] [<c000dc80>] (__irq_svc+0x40/0x70) from
[<c0288af4>] (cpuidle_enter_state+0x50/0xe0)
[56274.419532] [<c0288af4>] (cpuidle_enter_state+0x50/0xe0) from
[<c0288c34>] (cpuidle_idle_call+0xb0/0x148)
[56274.429080] [<c0288c34>] (cpuidle_idle_call+0xb0/0x148) from
[<c000f3ac>] (arch_cpu_idle+0x8/0x38)
[56274.438016] [<c000f3ac>] (arch_cpu_idle+0x8/0x38) from
[<c0059344>] (cpu_startup_entry+0xfc/0x140)
[56274.446956] [<c0059344>] (cpu_startup_entry+0xfc/0x140) from
[<c04a3a54>] (start_kernel+0x2d8/0x2e4)
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All SiRFSoC UART registers are in 32-bits. If we use writeb for
TXFIFO, actually all of 32-bits are still written, for TXTIFO,
only low 8-bits are valid, so in prima2&atlas6, this causes no
problem.
But in the new atlas7, using writeb to write UART registers will
cause an imprecise data abort as HW does check the "wrong" writeb.
So move to writel and this also makes the code consistent with
sirfsoc_uart_pio_tx_chars() in which we use writel.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Two new drivers have been added since 3.14, the MEN 16z135 uart, and
the ARM semihosting console. Both are missing an explicit 'select
SERIAL_CORE', which can leads build errors when no other driver
selects the core, as found during ARM randconfig testing.
In case of the ARM semihosting console, we also have to select
SERIAL_CORE_CONSOLE.
This adds the missing 'select' statements.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes the warnings:
drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_handle_rx':
>> drivers/tty/serial/sc16is7xx.c:548:1: warning: 'sc16is7xx_handle_rx' uses dynamic stack allocation [enabled by default]
drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_handle_tx':
>> drivers/tty/serial/sc16is7xx.c:589:1: warning: 'sc16is7xx_handle_tx' uses dynamic stack allocation [enabled by default]
Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/sc16is7xx.c:1060:12: warning: 'sc16is7xx_probe' defined but not used [-Wunused-function]
static int sc16is7xx_probe(struct device *dev,
^
drivers/tty/serial/sc16is7xx.c:1176:12: warning: 'sc16is7xx_remove' defined but not used [-Wunused-function]
static int sc16is7xx_remove(struct device *dev)
^
drivers/tty/serial/sc16is7xx.c:1215:29: warning: 'regcfg' defined but not used [-Wunused-variable]
static struct regmap_config regcfg = {
^
Fixed these warnings by removing the `#ifdef CONFIG_REGMAP_I2C' around their
calls as this driver selects REGMAP_I2C in Kconfig. This part of driver just
didn't compile at all when REGMAP_I2C configured as module (CONFIG_REGMAP_I2C
is not defined, just CONFIG_REGMAP_I2C_MODULE).
Signed-off-by: Jan Moskyto Matejka <mq@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On initialization failure, an error message is already printed with
level KERN_ERR, no need to print another one with level KERN_INFO.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pch_uart driver is for a companion chip to the Intel Atom E600
series processors. These are 32-bit x86 processors so the driver is
only needed on X86_32. Add COMPILE_TEST as an alternative, so that the
driver can still be build-tested elsewhere.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9aac588759 (tty/serial: add generic serial earlycon) moved
console option parsing from 8250_early.c and converted to kstrto*
functions from simple_strtoul along the way. However, kstrto* functions
are not equivalent in that they do not allow non-convertible characters
at the end such as "115200n8". Fix this by changing back to
simple_strtoul and ignore what checkpatch.pl says.
Reported-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d2fd6810a8 (tty/serial: convert 8250 to generic earlycon)
removed setup_early_serial8250_console, but there are still 2 callers
in:
arch/mips/mti-malta/malta-init.c
drivers/firmware/pcdp.c
Add back the function implemented as a wrapper to setup_earlycon.
Reported-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix by including linux/uaccess.h:
drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_ioctl':
>> drivers/tty/serial/sc16is7xx.c:861:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/sc16is7xx.c:867:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SC16IS7xx is a slave I2C-bus/SPI interface to a single-channel
high performance UART. The SC16IS7xx's internal register set is
backward-compatible with the widely used and widely popular 16C450.
The SC16IS7xx also provides additional advanced features such as
auto hardware and software flow control, automatic RS-485 support, and
software reset.
Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add earlycon support for the arm/arm64 semihosting debug serial
interface. This allows enabling a debug console when early_params are
processed. This is based on the arm64 earlyprintk smh support and is
intended to replace it.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add earlycon support for the pl011 serial port. This allows enabling
the pl011 for console when early_params are processed. This is based
on the arm64 earlyprintk support and is intended to replace it.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the generic earlycon infrastructure in place, convert the 8250
early console to use it.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This introduces generic earlycon infrastructure for serial devices
based on the 8250 earlycon. This allows for supporting earlycon option
with other serial devices. The earlycon output is enabled at the time
early_params are processed.
Only architectures that have fixmap support or have functional ioremap
when early_params are processed are supported. This is the same
restriction that the 8250 driver had.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add driver for MEN's 16z135 High Speed UART.
The 16z135 is a memory mapped UART Core on an MCB FPGA and has 1024 byte
deep FIFO buffers for the RX and TX path. It also has configurable FIFO
fill level IRQs and data copied to and from the hardware has to be
acknowledged.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Reviewed-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Zynq's UART is Cadence IP. Make this visible in the prompt in kconfig
and additional comments in the driver.
This also renames functions and symbols, as far as possible without
breaking user space API, to reflect the Cadence origin. This is achieved
through simple search and replace:
- s/XUARTPS/CDNS_UART/g
- s/xuartps/cdns_uart/g
The only exceptions are PORT_XUARTPS and the driver name, which stay as is,
due to their exposure to user space. As well as the - no legacy -
compatibility string 'xlnx,xuartps'
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A comment states, that, according to the data sheet, to enable
interrupts the disable register should be written, but the enable
register could be left untouched. And it suspsects a HW bug requiring
to write both.
Reviewing the data sheet, these statements seem wrong. Just as one would
expect. Writing to the enable/disable register enables/disables
interrupts.
Hence the misleading comment and needless write to the disable register
are removed from the enable sequence.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A lot of read-modify-write sequences used a one-line statement which
nests a readl() within a writel(). Convert this into code sequences that
make the three steps more obvious.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Qipan Li
Barry Song
Arnd Bergmann
Jon Ringle
Jan Moskyto Matejka
Jean Delvare
Rob Herring
Greg Kroah-Hartman
Johannes Thumshirn
Soren Brinkmann