linux_dsm_epyc7002/drivers/tty/serial/mcf.c

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tty: add SPDX identifiers to all remaining files in drivers/tty/ It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 00:11:51 +07:00
// SPDX-License-Identifier: GPL-2.0+
/****************************************************************************/
/*
* mcf.c -- Freescale ColdFire UART driver
*
* (C) Copyright 2003-2007, Greg Ungerer <gerg@uclinux.org>
*/
/****************************************************************************/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfuart.h>
#include <asm/nettel.h>
/****************************************************************************/
/*
* Some boards implement the DTR/DCD lines using GPIO lines, most
* don't. Dummy out the access macros for those that don't. Those
* that do should define these macros somewhere in there board
* specific inlude files.
*/
#if !defined(mcf_getppdcd)
#define mcf_getppdcd(p) (1)
#endif
#if !defined(mcf_getppdtr)
#define mcf_getppdtr(p) (1)
#endif
#if !defined(mcf_setppdtr)
#define mcf_setppdtr(p, v) do { } while (0)
#endif
/****************************************************************************/
/*
* Local per-uart structure.
*/
struct mcf_uart {
struct uart_port port;
unsigned int sigs; /* Local copy of line sigs */
unsigned char imr; /* Local IMR mirror */
};
/****************************************************************************/
static unsigned int mcf_tx_empty(struct uart_port *port)
{
return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
TIOCSER_TEMT : 0;
}
/****************************************************************************/
static unsigned int mcf_get_mctrl(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
unsigned int sigs;
sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
0 : TIOCM_CTS;
sigs |= (pp->sigs & TIOCM_RTS);
sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
return sigs;
}
/****************************************************************************/
static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
pp->sigs = sigs;
mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
if (sigs & TIOCM_RTS)
writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
else
writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
}
/****************************************************************************/
static void mcf_start_tx(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
if (port->rs485.flags & SER_RS485_ENABLED) {
/* Enable Transmitter */
writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
/* Manually assert RTS */
writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
}
pp->imr |= MCFUART_UIR_TXREADY;
writeb(pp->imr, port->membase + MCFUART_UIMR);
}
/****************************************************************************/
static void mcf_stop_tx(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
pp->imr &= ~MCFUART_UIR_TXREADY;
writeb(pp->imr, port->membase + MCFUART_UIMR);
}
/****************************************************************************/
static void mcf_stop_rx(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
pp->imr &= ~MCFUART_UIR_RXREADY;
writeb(pp->imr, port->membase + MCFUART_UIMR);
}
/****************************************************************************/
static void mcf_break_ctl(struct uart_port *port, int break_state)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
if (break_state == -1)
writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
else
writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
spin_unlock_irqrestore(&port->lock, flags);
}
/****************************************************************************/
static int mcf_startup(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
/* Reset UART, get it into known state... */
writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
/* Enable the UART transmitter and receiver */
writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
port->membase + MCFUART_UCR);
/* Enable RX interrupts now */
pp->imr = MCFUART_UIR_RXREADY;
writeb(pp->imr, port->membase + MCFUART_UIMR);
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
/****************************************************************************/
static void mcf_shutdown(struct uart_port *port)
{
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
/* Disable all interrupts now */
pp->imr = 0;
writeb(pp->imr, port->membase + MCFUART_UIMR);
/* Disable UART transmitter and receiver */
writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
spin_unlock_irqrestore(&port->lock, flags);
}
/****************************************************************************/
static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned long flags;
unsigned int baud, baudclk;
#if defined(CONFIG_M5272)
unsigned int baudfr;
#endif
unsigned char mr1, mr2;
baud = uart_get_baud_rate(port, termios, old, 0, 230400);
#if defined(CONFIG_M5272)
baudclk = (MCF_BUSCLK / baud) / 32;
baudfr = (((MCF_BUSCLK / baud) + 1) / 2) % 16;
#else
baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
#endif
mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
mr2 = 0;
switch (termios->c_cflag & CSIZE) {
case CS5: mr1 |= MCFUART_MR1_CS5; break;
case CS6: mr1 |= MCFUART_MR1_CS6; break;
case CS7: mr1 |= MCFUART_MR1_CS7; break;
case CS8:
default: mr1 |= MCFUART_MR1_CS8; break;
}
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD)
mr1 |= MCFUART_MR1_PARITYMARK;
else
mr1 |= MCFUART_MR1_PARITYSPACE;
} else {
if (termios->c_cflag & PARODD)
mr1 |= MCFUART_MR1_PARITYODD;
else
mr1 |= MCFUART_MR1_PARITYEVEN;
}
} else {
mr1 |= MCFUART_MR1_PARITYNONE;
}
serial: Fix IGNBRK handling If IGNBRK is set without either BRKINT or PARMRK set, some uart drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the line discipline, when it should send either nothing or the TTYBREAK flag set. This happens because the read_status_mask masks out the BI condition, which uart_insert_char() then interprets as a normal 0x00 byte. SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General Terminal Interface - Input Modes, states: "If IGNBRK is set, a break condition detected on input shall be ignored; that is, not put on the input queue and therefore not read by any process." Fix read_status_mask to include the BI bit if IGNBRK is set; the lsr status retains the BI bit if a BREAK is recv'd, which is subsequently ignored in uart_insert_char() when masked with the ignore_status_mask. Affected drivers: 8250 - all serial_txx9 mfd amba-pl010 amba-pl011 atmel_serial bfin_uart dz ip22zilog max310x mxs-auart netx-serial pnx8xxx_uart pxa sb1250-duart sccnxp serial_ks8695 sirfsoc_uart st-asc vr41xx_siu zs sunzilog fsl_lpuart sunsab ucc_uart bcm63xx_uart sunsu efm32-uart pmac_zilog mpsc msm_serial m32r_sio Unaffected drivers: omap-serial rp2 sa1100 imx icom Annotated for fixes: altera_uart mcf Drivers without break detection: 21285 xilinx-uartps altera_jtaguart apbuart arc-uart clps711x max3100 uartlite msm_serial_hs nwpserial lantiq vt8500_serial Unknown: samsung mpc52xx_uart bfin_sport_uart cpm_uart/core Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag' Reported-by: Ivan <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-16 19:10:41 +07:00
/*
* FIXME: port->read_status_mask and port->ignore_status_mask
* need to be initialized based on termios settings for
* INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
*/
if (termios->c_cflag & CSTOPB)
mr2 |= MCFUART_MR2_STOP2;
else
mr2 |= MCFUART_MR2_STOP1;
if (termios->c_cflag & CRTSCTS) {
mr1 |= MCFUART_MR1_RXRTS;
mr2 |= MCFUART_MR2_TXCTS;
}
spin_lock_irqsave(&port->lock, flags);
if (port->rs485.flags & SER_RS485_ENABLED) {
dev_dbg(port->dev, "Setting UART to RS485\n");
mr2 |= MCFUART_MR2_TXRTS;
}
uart_update_timeout(port, termios->c_cflag, baud);
writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
writeb(mr1, port->membase + MCFUART_UMR);
writeb(mr2, port->membase + MCFUART_UMR);
writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
#if defined(CONFIG_M5272)
writeb((baudfr & 0x0f), port->membase + MCFUART_UFPD);
#endif
writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
port->membase + MCFUART_UCSR);
writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
port->membase + MCFUART_UCR);
spin_unlock_irqrestore(&port->lock, flags);
}
/****************************************************************************/
static void mcf_rx_chars(struct mcf_uart *pp)
{
struct uart_port *port = &pp->port;
unsigned char status, ch, flag;
while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
ch = readb(port->membase + MCFUART_URB);
flag = TTY_NORMAL;
port->icount.rx++;
if (status & MCFUART_USR_RXERR) {
writeb(MCFUART_UCR_CMDRESETERR,
port->membase + MCFUART_UCR);
if (status & MCFUART_USR_RXBREAK) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
} else if (status & MCFUART_USR_RXPARITY) {
port->icount.parity++;
} else if (status & MCFUART_USR_RXOVERRUN) {
port->icount.overrun++;
} else if (status & MCFUART_USR_RXFRAMING) {
port->icount.frame++;
}
status &= port->read_status_mask;
if (status & MCFUART_USR_RXBREAK)
flag = TTY_BREAK;
else if (status & MCFUART_USR_RXPARITY)
flag = TTY_PARITY;
else if (status & MCFUART_USR_RXFRAMING)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, ch))
continue;
uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
}
tty: serial: mcf: drop uart_port->lock before calling tty_flip_buffer_push() The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-19 21:44:17 +07:00
spin_unlock(&port->lock);
tty_flip_buffer_push(&port->state->port);
tty: serial: mcf: drop uart_port->lock before calling tty_flip_buffer_push() The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-19 21:44:17 +07:00
spin_lock(&port->lock);
}
/****************************************************************************/
static void mcf_tx_chars(struct mcf_uart *pp)
{
struct uart_port *port = &pp->port;
struct circ_buf *xmit = &port->state->xmit;
if (port->x_char) {
/* Send special char - probably flow control */
writeb(port->x_char, port->membase + MCFUART_UTB);
port->x_char = 0;
port->icount.tx++;
return;
}
while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
if (xmit->head == xmit->tail)
break;
writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
port->icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (xmit->head == xmit->tail) {
pp->imr &= ~MCFUART_UIR_TXREADY;
writeb(pp->imr, port->membase + MCFUART_UIMR);
/* Disable TX to negate RTS automatically */
if (port->rs485.flags & SER_RS485_ENABLED)
writeb(MCFUART_UCR_TXDISABLE,
port->membase + MCFUART_UCR);
}
}
/****************************************************************************/
static irqreturn_t mcf_interrupt(int irq, void *data)
{
struct uart_port *port = data;
struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
unsigned int isr;
irqreturn_t ret = IRQ_NONE;
isr = readb(port->membase + MCFUART_UISR) & pp->imr;
spin_lock(&port->lock);
if (isr & MCFUART_UIR_RXREADY) {
mcf_rx_chars(pp);
ret = IRQ_HANDLED;
}
if (isr & MCFUART_UIR_TXREADY) {
mcf_tx_chars(pp);
ret = IRQ_HANDLED;
}
spin_unlock(&port->lock);
return ret;
}
/****************************************************************************/
static void mcf_config_port(struct uart_port *port, int flags)
{
port->type = PORT_MCF;
port->fifosize = MCFUART_TXFIFOSIZE;
/* Clear mask, so no surprise interrupts. */
writeb(0, port->membase + MCFUART_UIMR);
if (request_irq(port->irq, mcf_interrupt, 0, "UART", port))
printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
"interrupt vector=%d\n", port->line, port->irq);
}
/****************************************************************************/
static const char *mcf_type(struct uart_port *port)
{
return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
}
/****************************************************************************/
static int mcf_request_port(struct uart_port *port)
{
/* UARTs always present */
return 0;
}
/****************************************************************************/
static void mcf_release_port(struct uart_port *port)
{
/* Nothing to release... */
}
/****************************************************************************/
static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
return -EINVAL;
return 0;
}
/****************************************************************************/
/* Enable or disable the RS485 support */
static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
{
unsigned char mr1, mr2;
/* Get mode registers */
mr1 = readb(port->membase + MCFUART_UMR);
mr2 = readb(port->membase + MCFUART_UMR);
if (rs485->flags & SER_RS485_ENABLED) {
dev_dbg(port->dev, "Setting UART to RS485\n");
/* Automatically negate RTS after TX completes */
mr2 |= MCFUART_MR2_TXRTS;
} else {
dev_dbg(port->dev, "Setting UART to RS232\n");
mr2 &= ~MCFUART_MR2_TXRTS;
}
writeb(mr1, port->membase + MCFUART_UMR);
writeb(mr2, port->membase + MCFUART_UMR);
port->rs485 = *rs485;
return 0;
}
/****************************************************************************/
/*
* Define the basic serial functions we support.
*/
static const struct uart_ops mcf_uart_ops = {
.tx_empty = mcf_tx_empty,
.get_mctrl = mcf_get_mctrl,
.set_mctrl = mcf_set_mctrl,
.start_tx = mcf_start_tx,
.stop_tx = mcf_stop_tx,
.stop_rx = mcf_stop_rx,
.break_ctl = mcf_break_ctl,
.startup = mcf_startup,
.shutdown = mcf_shutdown,
.set_termios = mcf_set_termios,
.type = mcf_type,
.request_port = mcf_request_port,
.release_port = mcf_release_port,
.config_port = mcf_config_port,
.verify_port = mcf_verify_port,
};
static struct mcf_uart mcf_ports[4];
#define MCF_MAXPORTS ARRAY_SIZE(mcf_ports)
/****************************************************************************/
#if defined(CONFIG_SERIAL_MCF_CONSOLE)
/****************************************************************************/
int __init early_mcf_setup(struct mcf_platform_uart *platp)
{
struct uart_port *port;
int i;
for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
port = &mcf_ports[i].port;
port->line = i;
port->type = PORT_MCF;
port->mapbase = platp[i].mapbase;
port->membase = (platp[i].membase) ? platp[i].membase :
(unsigned char __iomem *) port->mapbase;
port->iotype = SERIAL_IO_MEM;
port->irq = platp[i].irq;
port->uartclk = MCF_BUSCLK;
port->flags = UPF_BOOT_AUTOCONF;
port->rs485_config = mcf_config_rs485;
port->ops = &mcf_uart_ops;
}
return 0;
}
/****************************************************************************/
static void mcf_console_putc(struct console *co, const char c)
{
struct uart_port *port = &(mcf_ports + co->index)->port;
int i;
for (i = 0; (i < 0x10000); i++) {
if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
break;
}
writeb(c, port->membase + MCFUART_UTB);
for (i = 0; (i < 0x10000); i++) {
if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
break;
}
}
/****************************************************************************/
static void mcf_console_write(struct console *co, const char *s, unsigned int count)
{
for (; (count); count--, s++) {
mcf_console_putc(co, *s);
if (*s == '\n')
mcf_console_putc(co, '\r');
}
}
/****************************************************************************/
static int __init mcf_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = CONFIG_SERIAL_MCF_BAUDRATE;
int bits = 8;
int parity = 'n';
int flow = 'n';
if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
co->index = 0;
port = &mcf_ports[co->index].port;
if (port->membase == 0)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
/****************************************************************************/
static struct uart_driver mcf_driver;
static struct console mcf_console = {
.name = "ttyS",
.write = mcf_console_write,
.device = uart_console_device,
.setup = mcf_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &mcf_driver,
};
static int __init mcf_console_init(void)
{
register_console(&mcf_console);
return 0;
}
console_initcall(mcf_console_init);
#define MCF_CONSOLE &mcf_console
/****************************************************************************/
#else
/****************************************************************************/
#define MCF_CONSOLE NULL
/****************************************************************************/
#endif /* CONFIG_SERIAL_MCF_CONSOLE */
/****************************************************************************/
/*
* Define the mcf UART driver structure.
*/
static struct uart_driver mcf_driver = {
.owner = THIS_MODULE,
.driver_name = "mcf",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = MCF_MAXPORTS,
.cons = MCF_CONSOLE,
};
/****************************************************************************/
static int mcf_probe(struct platform_device *pdev)
{
struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
struct uart_port *port;
int i;
for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
port = &mcf_ports[i].port;
port->line = i;
port->type = PORT_MCF;
port->mapbase = platp[i].mapbase;
port->membase = (platp[i].membase) ? platp[i].membase :
(unsigned char __iomem *) platp[i].mapbase;
port->dev = &pdev->dev;
port->iotype = SERIAL_IO_MEM;
port->irq = platp[i].irq;
port->uartclk = MCF_BUSCLK;
port->ops = &mcf_uart_ops;
port->flags = UPF_BOOT_AUTOCONF;
port->rs485_config = mcf_config_rs485;
uart_add_one_port(&mcf_driver, port);
}
return 0;
}
/****************************************************************************/
static int mcf_remove(struct platform_device *pdev)
{
struct uart_port *port;
int i;
for (i = 0; (i < MCF_MAXPORTS); i++) {
port = &mcf_ports[i].port;
if (port)
uart_remove_one_port(&mcf_driver, port);
}
return 0;
}
/****************************************************************************/
static struct platform_driver mcf_platform_driver = {
.probe = mcf_probe,
.remove = mcf_remove,
.driver = {
.name = "mcfuart",
},
};
/****************************************************************************/
static int __init mcf_init(void)
{
int rc;
printk("ColdFire internal UART serial driver\n");
rc = uart_register_driver(&mcf_driver);
if (rc)
return rc;
rc = platform_driver_register(&mcf_platform_driver);
if (rc) {
uart_unregister_driver(&mcf_driver);
return rc;
}
return 0;
}
/****************************************************************************/
static void __exit mcf_exit(void)
{
platform_driver_unregister(&mcf_platform_driver);
uart_unregister_driver(&mcf_driver);
}
/****************************************************************************/
module_init(mcf_init);
module_exit(mcf_exit);
MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
MODULE_DESCRIPTION("Freescale ColdFire UART driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mcfuart");
/****************************************************************************/