From 2c7af5ba65cfb0145ad8e11f856035c10ba0d22c Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Mon, 2 Mar 2015 10:18:18 +0100 Subject: tty: serial: atmel: rework interrupt and wakeup handling The IRQ line connected to the DBGU UART is often shared with a timer device which request the IRQ with IRQF_NO_SUSPEND. Since the UART driver is correctly disabling IRQs when entering suspend we can safely request the IRQ with IRQF_COND_SUSPEND so that irq core will not complain about mixing IRQF_NO_SUSPEND and !IRQF_NO_SUSPEND. Rework the interrupt handler to wake the system up when an interrupt happens on the DEBUG_UART while the system is suspended. Signed-off-by: Boris Brezillon Reviewed-by: Alexandre Belloni Acked-by: Nicolas Ferre Acked-by: Mark Rutland Signed-off-by: Rafael J. Wysocki --- drivers/tty/serial/atmel_serial.c | 49 +++++++++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 4 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 846552bff67d..4e959c43f680 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include @@ -173,6 +174,12 @@ struct atmel_uart_port { bool ms_irq_enabled; bool is_usart; /* usart or uart */ struct timer_list uart_timer; /* uart timer */ + + bool suspended; + unsigned int pending; + unsigned int pending_status; + spinlock_t lock_suspended; + int (*prepare_rx)(struct uart_port *port); int (*prepare_tx)(struct uart_port *port); void (*schedule_rx)(struct uart_port *port); @@ -1179,12 +1186,15 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - unsigned int status, pending, pass_counter = 0; + unsigned int status, pending, mask, pass_counter = 0; bool gpio_handled = false; + spin_lock(&atmel_port->lock_suspended); + do { status = atmel_get_lines_status(port); - pending = status & UART_GET_IMR(port); + mask = UART_GET_IMR(port); + pending = status & mask; if (!gpio_handled) { /* * Dealing with GPIO interrupt @@ -1206,11 +1216,21 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id) if (!pending) break; + if (atmel_port->suspended) { + atmel_port->pending |= pending; + atmel_port->pending_status = status; + UART_PUT_IDR(port, mask); + pm_system_wakeup(); + break; + } + atmel_handle_receive(port, pending); atmel_handle_status(port, pending, status); atmel_handle_transmit(port, pending); } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT); + spin_unlock(&atmel_port->lock_suspended); + return pass_counter ? IRQ_HANDLED : IRQ_NONE; } @@ -1742,7 +1762,8 @@ static int atmel_startup(struct uart_port *port) /* * Allocate the IRQ */ - retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, + retval = request_irq(port->irq, atmel_interrupt, + IRQF_SHARED | IRQF_COND_SUSPEND, tty ? tty->name : "atmel_serial", port); if (retval) { dev_err(port->dev, "atmel_startup - Can't get irq\n"); @@ -2513,8 +2534,14 @@ static int atmel_serial_suspend(struct platform_device *pdev, /* we can not wake up if we're running on slow clock */ atmel_port->may_wakeup = device_may_wakeup(&pdev->dev); - if (atmel_serial_clk_will_stop()) + if (atmel_serial_clk_will_stop()) { + unsigned long flags; + + spin_lock_irqsave(&atmel_port->lock_suspended, flags); + atmel_port->suspended = true; + spin_unlock_irqrestore(&atmel_port->lock_suspended, flags); device_set_wakeup_enable(&pdev->dev, 0); + } uart_suspend_port(&atmel_uart, port); @@ -2525,6 +2552,18 @@ static int atmel_serial_resume(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + unsigned long flags; + + spin_lock_irqsave(&atmel_port->lock_suspended, flags); + if (atmel_port->pending) { + atmel_handle_receive(port, atmel_port->pending); + atmel_handle_status(port, atmel_port->pending, + atmel_port->pending_status); + atmel_handle_transmit(port, atmel_port->pending); + atmel_port->pending = 0; + } + atmel_port->suspended = false; + spin_unlock_irqrestore(&atmel_port->lock_suspended, flags); uart_resume_port(&atmel_uart, port); device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup); @@ -2593,6 +2632,8 @@ static int atmel_serial_probe(struct platform_device *pdev) port->backup_imr = 0; port->uart.line = ret; + spin_lock_init(&port->lock_suspended); + ret = atmel_init_gpios(port, &pdev->dev); if (ret < 0) dev_err(&pdev->dev, "%s", -- cgit v1.2.3 From 045f32dda9477d3ddf31a4fa862c487d0f747e33 Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Mon, 16 Feb 2015 08:27:49 +0200 Subject: Revert "tty/serial: of_serial: add DT alias ID handling" This reverts commit 6d01bb9dc82a60580f749062a48cb47cd5caca07. The exact same code was added in commit 3239fd31d4 (serial: of-serial: fetch line number from DT) a few lined above. Doing this once should be enough. Cc: Rob Herring Signed-off-by: Baruch Siach Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/of_serial.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 7ff61e24a195..33fb94f78967 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c @@ -133,10 +133,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev, if (of_find_property(np, "no-loopback-test", NULL)) port->flags |= UPF_SKIP_TEST; - ret = of_alias_get_id(np, "serial"); - if (ret >= 0) - port->line = ret; - port->dev = &ofdev->dev; switch (type) { -- cgit v1.2.3 From ca8bb4aefb932e3da105f28cbfba36d57a931081 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Sun, 15 Feb 2015 18:32:16 +0100 Subject: serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO" This reverts commit 0aa525d11859c1a4d5b78fdc704148e2ae03ae13. The conditional RX-FIFO read seems to cause spurious interrupts and we see just: |serial8250: too much work for irq29 The previous behaviour was "default" for decades and Marvell's 88f6282 SoC might not be the only that relies on it. Therefore the Omap fix is reverted for now. Fixes: 0aa525d11859 ("tty: serial: 8250_core: read only RX if there is something in the FIFO") Reported-By: Nicolas Schichan Debuged-By: Peter Hurley Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index e3b9570a1eff..deae122c9c4b 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2138,8 +2138,8 @@ int serial8250_do_startup(struct uart_port *port) /* * Clear the interrupt registers. */ - if (serial_port_in(port, UART_LSR) & UART_LSR_DR) - serial_port_in(port, UART_RX); + serial_port_in(port, UART_LSR); + serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); @@ -2300,8 +2300,8 @@ dont_test_tx_en: * saved flags to avoid getting false values from polling * routines or the previous session. */ - if (serial_port_in(port, UART_LSR) & UART_LSR_DR) - serial_port_in(port, UART_RX); + serial_port_in(port, UART_LSR); + serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); up->lsr_saved_flags = 0; @@ -2394,8 +2394,7 @@ void serial8250_do_shutdown(struct uart_port *port) * Read data port to reset things, and then unlink from * the IRQ chain. */ - if (serial_port_in(port, UART_LSR) & UART_LSR_DR) - serial_port_in(port, UART_RX); + serial_port_in(port, UART_RX); serial8250_rpm_put(up); del_timer_sync(&up->timer); -- cgit v1.2.3 From f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 6 Mar 2015 10:49:21 +0000 Subject: Change email address for 8250_pci I'm still receiving reports to my email address, so let's point this at the linux-serial mailing list instead. Cc: Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index daf2c82984e9..65dd3ad442ea 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -69,7 +69,7 @@ static void moan_device(const char *str, struct pci_dev *dev) "Please send the output of lspci -vv, this\n" "message (0x%04x,0x%04x,0x%04x,0x%04x), the\n" "manufacturer and name of serial board or\n" - "modem board to rmk+serial@arm.linux.org.uk.\n", + "modem board to .\n", pci_name(dev), str, dev->vendor, dev->device, dev->subsystem_vendor, dev->subsystem_device); } -- cgit v1.2.3 From 6262a3692b921a82075695c5c6d10f4a6bcc5fac Mon Sep 17 00:00:00 2001 From: Wang YanQing Date: Sat, 7 Mar 2015 01:13:03 +0800 Subject: serial:8250:8250_pci: fix redundant entry report for WCH_CH352_2S Commit 8b5c913f7ee6464849570bacb6bcd9ef0eaf7dce ("serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection") trigger one redundant entry report message. This patch fix it. Reported-by: Russell King Signed-off-by: Wang YanQing Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 65dd3ad442ea..285b875fd187 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -5415,10 +5415,6 @@ static struct pci_device_id serial_pci_tbl[] = { PCI_ANY_ID, PCI_ANY_ID, 0, 0, pbn_b0_bt_2_115200 }, - { PCI_VENDOR_ID_WCH, PCI_DEVICE_ID_WCH_CH352_2S, - PCI_ANY_ID, PCI_ANY_ID, - 0, 0, pbn_b0_bt_2_115200 }, - { PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH384_4S, PCI_ANY_ID, PCI_ANY_ID, 0, 0, pbn_wch384_4 }, -- cgit v1.2.3 From 7cf91108d44dbef3d48766fd0e7f7347c2e48bda Mon Sep 17 00:00:00 2001 From: Wang YanQing Date: Sat, 7 Mar 2015 01:08:35 +0800 Subject: serial:8250:8250_pci: delete unneeded quirk entries These quirk entries have the same effect as default quirk entry, so we can just delete them. Signed-off-by: Wang YanQing Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 285b875fd187..892eb32cdef4 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1987,13 +1987,6 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = { .subdevice = PCI_ANY_ID, .setup = byt_serial_setup, }, - { - .vendor = PCI_VENDOR_ID_INTEL, - .device = PCI_DEVICE_ID_INTEL_QRK_UART, - .subvendor = PCI_ANY_ID, - .subdevice = PCI_ANY_ID, - .setup = pci_default_setup, - }, { .vendor = PCI_VENDOR_ID_INTEL, .device = PCI_DEVICE_ID_INTEL_BSW_UART1, @@ -2199,13 +2192,6 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = { /* * PLX */ - { - .vendor = PCI_VENDOR_ID_PLX, - .device = PCI_DEVICE_ID_PLX_9030, - .subvendor = PCI_SUBVENDOR_ID_PERLE, - .subdevice = PCI_ANY_ID, - .setup = pci_default_setup, - }, { .vendor = PCI_VENDOR_ID_PLX, .device = PCI_DEVICE_ID_PLX_9050, -- cgit v1.2.3 From dfd37668ea6d5029fb5d8a66ea5e202d0655fad7 Mon Sep 17 00:00:00 2001 From: Desmond Liu Date: Thu, 26 Feb 2015 16:35:57 -0800 Subject: serial: 8250_dw: Fix get_mctrl behaviour Fixed behaviour of get_mctrl() serial driver function as documented in: https://www.kernel.org/doc/Documentation/serial/driver Added device-tree properties 'dcd-override', 'dsr-override', 'cts-override', and 'ri-override' specific to the Synopsis 8250 DesignWare UART driver. Allows one to force Data Carrier Detect, Clear To Send, and Data Set Ready signals to permanently be reported as active. The Ring indicator can be forced to be reported as inactive. It is possible that if modem control signalling is enabled on a port that doesn't have these pins (e.g. - a simple two wire Tx/Rx port), the driver can hang indefinitely waiting for the state to change. The new DT properties allow the driver to ignore the state of these pins on serial ports that don't support them, as recommended in the kernel documentation. Reviewed-by: JD (Jiandong) Zheng Signed-off-by: Jonathan Richardson Signed-off-by: Greg Kroah-Hartman --- .../bindings/serial/snps-dw-apb-uart.txt | 16 +++++++++++ drivers/tty/serial/8250/8250_dw.c | 32 ++++++++++++++++++++++ 2 files changed, 48 insertions(+) (limited to 'drivers/tty') diff --git a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt index 7f76214f728a..289c40ed7470 100644 --- a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt +++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt @@ -21,6 +21,18 @@ Optional properties: - reg-io-width : the size (in bytes) of the IO accesses that should be performed on the device. If this property is not present then single byte accesses are used. +- dcd-override : Override the DCD modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- dsr-override : Override the DTS modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- cts-override : Override the CTS modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- ri-override : Override the RI modem status signal. This signal will always be + reported as inactive instead of being obtained from the modem status register. + Define this if your serial port does not use this pin. Example: @@ -31,6 +43,10 @@ Example: interrupts = <10>; reg-shift = <2>; reg-io-width = <4>; + dcd-override; + dsr-override; + cts-override; + ri-override; }; Example with one clock: diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index e60116235836..2ab229ddee38 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -59,6 +59,8 @@ struct dw8250_data { u8 usr_reg; int last_mcr; int line; + int msr_mask_on; + int msr_mask_off; struct clk *clk; struct clk *pclk; struct reset_control *rst; @@ -81,6 +83,12 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) value &= ~UART_MSR_DCTS; } + /* Override any modem control signals if needed */ + if (offset == UART_MSR) { + value |= d->msr_mask_on; + value &= ~d->msr_mask_off; + } + return value; } @@ -334,6 +342,30 @@ static int dw8250_probe_of(struct uart_port *p, if (id >= 0) p->line = id; + if (of_property_read_bool(np, "dcd-override")) { + /* Always report DCD as active */ + data->msr_mask_on |= UART_MSR_DCD; + data->msr_mask_off |= UART_MSR_DDCD; + } + + if (of_property_read_bool(np, "dsr-override")) { + /* Always report DSR as active */ + data->msr_mask_on |= UART_MSR_DSR; + data->msr_mask_off |= UART_MSR_DDSR; + } + + if (of_property_read_bool(np, "cts-override")) { + /* Always report DSR as active */ + data->msr_mask_on |= UART_MSR_DSR; + data->msr_mask_off |= UART_MSR_DDSR; + } + + if (of_property_read_bool(np, "ri-override")) { + /* Always report Ring indicator as inactive */ + data->msr_mask_off |= UART_MSR_RI; + data->msr_mask_off |= UART_MSR_TERI; + } + /* clock got configured through clk api, all done */ if (p->uartclk) return 0; -- cgit v1.2.3 From f0bf0bd07943bfde8f5ac39a32664810a379c7d3 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Fri, 27 Feb 2015 18:40:31 +0100 Subject: tty: fix up atime/mtime mess, take four This problem was taken care of three times already in * b0de59b5733d18b0d1974a060860a8b5c1b36a2e (TTY: do not update atime/mtime on read/write), * 37b7f3c76595e23257f61bd80b223de8658617ee (TTY: fix atime/mtime regression), and * b0b885657b6c8ef63a46bc9299b2a7715d19acde (tty: fix up atime/mtime mess, take three) But it still misses one point. As John Paul correctly points out, we do not care about setting date. If somebody ever changes wall time backwards (by mistake for example), tty timestamps are never updated until the original wall time passes. So check the absolute difference of times and if it large than "8 seconds or so", always update the time. That means we will update immediatelly when changing time. Ergo, CAP_SYS_TIME can foul the check, but it was always that way. Thanks John for serving me this so nicely debugged. Signed-off-by: Jiri Slaby Reported-by: John Paul Perry Cc: # all, as b0b885657 was backported Acked-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 51f066aa375e..2bb4dfc02873 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1028,8 +1028,8 @@ EXPORT_SYMBOL(start_tty); /* We limit tty time update visibility to every 8 seconds or so. */ static void tty_update_time(struct timespec *time) { - unsigned long sec = get_seconds() & ~7; - if ((long)(sec - time->tv_sec) > 0) + unsigned long sec = get_seconds(); + if (abs(sec - time->tv_sec) & ~7) time->tv_sec = sec; } -- cgit v1.2.3 From c4e6dcfa00dab9b10e75bba835393b81f256310b Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Mon, 16 Feb 2015 22:39:04 +0800 Subject: serial: sprd: Fix missing spin_unlock in sprd_handle_irq() Fix return from sprd_handle_irq() with spin_lock held. Signed-off-by: Axel Lin Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sprd_serial.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c index 594b63331ef4..bca975f5093b 100644 --- a/drivers/tty/serial/sprd_serial.c +++ b/drivers/tty/serial/sprd_serial.c @@ -293,8 +293,10 @@ static irqreturn_t sprd_handle_irq(int irq, void *dev_id) ims = serial_in(port, SPRD_IMSR); - if (!ims) + if (!ims) { + spin_unlock(&port->lock); return IRQ_NONE; + } serial_out(port, SPRD_ICLR, ~0); -- cgit v1.2.3 From 6b270fd4db08fc13683d616a733d9cacdd3b4afa Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 4 Mar 2015 10:39:04 +0100 Subject: TTY: bfin_jtag_comm: remove incorrect wait_until_sent operation Remove incorrect and redundant wait_until_sent operation, which waits for the driver buffer rather than any hardware buffers to drain, something which is already taken care of by the tty layer (and chars_in_buffer). Signed-off-by: Johan Hovold Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/bfin_jtag_comm.c | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/bfin_jtag_comm.c b/drivers/tty/bfin_jtag_comm.c index d7b198c400c7..ce24182f8514 100644 --- a/drivers/tty/bfin_jtag_comm.c +++ b/drivers/tty/bfin_jtag_comm.c @@ -210,18 +210,6 @@ bfin_jc_chars_in_buffer(struct tty_struct *tty) return circ_cnt(&bfin_jc_write_buf); } -static void -bfin_jc_wait_until_sent(struct tty_struct *tty, int timeout) -{ - unsigned long expire = jiffies + timeout; - while (!circ_empty(&bfin_jc_write_buf)) { - if (signal_pending(current)) - break; - if (time_after(jiffies, expire)) - break; - } -} - static const struct tty_operations bfin_jc_ops = { .open = bfin_jc_open, .close = bfin_jc_close, @@ -230,7 +218,6 @@ static const struct tty_operations bfin_jc_ops = { .flush_chars = bfin_jc_flush_chars, .write_room = bfin_jc_write_room, .chars_in_buffer = bfin_jc_chars_in_buffer, - .wait_until_sent = bfin_jc_wait_until_sent, }; static int __init bfin_jc_init(void) -- cgit v1.2.3 From 79fbf4a550ed6a22e1ae1516113e6c7fa5d56a53 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 4 Mar 2015 10:39:06 +0100 Subject: TTY: fix tty_wait_until_sent on 64-bit machines Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an infinite timeout (0) would be passed to the underlying tty-driver's wait_until_sent-operation as a negative timeout (-1), causing it to return immediately. This manifests itself for example as tcdrain() returning immediately, drivers not honouring the drain flags when setting terminal attributes, or even dropped data on close as a requested infinite closing-wait timeout would be ignored. The first symptom was reported by Asier LLANO who noted that tcdrain() returned prematurely when using the ftdi_sio usb-serial driver. Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the underlying tty driver. Note that the serial-core wait_until_sent-implementation is not affected by this bug due to a lucky chance (comparison to an unsigned maximum timeout), and neither is the cyclades one that had an explicit check for negative timeouts, but all other tty drivers appear to be affected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable # v2.6.12 Reported-by: ZIV-Asier Llano Palacios Signed-off-by: Johan Hovold Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_ioctl.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index a5cf253b2544..89ae23ac9ae6 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -217,11 +217,17 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout) #endif if (!timeout) timeout = MAX_SCHEDULE_TIMEOUT; + if (wait_event_interruptible_timeout(tty->write_wait, - !tty_chars_in_buffer(tty), timeout) >= 0) { - if (tty->ops->wait_until_sent) - tty->ops->wait_until_sent(tty, timeout); + !tty_chars_in_buffer(tty), timeout) < 0) { + return; } + + if (timeout == MAX_SCHEDULE_TIMEOUT) + timeout = 0; + + if (tty->ops->wait_until_sent) + tty->ops->wait_until_sent(tty, timeout); } EXPORT_SYMBOL(tty_wait_until_sent); -- cgit v1.2.3 From c37bc682e30b8027054356214eb8a3aafbda8e37 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 4 Mar 2015 10:39:07 +0100 Subject: TTY: fix tty_wait_until_sent maximum timeout Currently tty_wait_until_sent may take up to twice as long as the requested timeout while waiting for driver and hardware buffers to drain. Fix this by taking the remaining number of jiffies after waiting for driver buffers to drain into account so that the timeout actually becomes a maximum timeout as it is documented to be. Note that this specifically implies tighter timings when closing a port as a consequence of actually honouring the port closing-wait setting for drivers relying on tty_wait_until_sent_from_close (e.g. via tty_port_close_start). Signed-off-by: Johan Hovold Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_ioctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 89ae23ac9ae6..632fc8152061 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -218,10 +218,10 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout) if (!timeout) timeout = MAX_SCHEDULE_TIMEOUT; - if (wait_event_interruptible_timeout(tty->write_wait, - !tty_chars_in_buffer(tty), timeout) < 0) { + timeout = wait_event_interruptible_timeout(tty->write_wait, + !tty_chars_in_buffer(tty), timeout); + if (timeout <= 0) return; - } if (timeout == MAX_SCHEDULE_TIMEOUT) timeout = 0; -- cgit v1.2.3 From 7fd6f640f2dd17dac6ddd6702c378cb0bb9cfa11 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 11 Mar 2015 09:19:16 -0400 Subject: serial: 8250_dw: Fix deadlock in LCR workaround Trying to write console output from within the serial console driver while the port->lock is held causes recursive deadlock: CPU 0 spin_lock_irqsave(&port->lock) printk() console_unlock() call_console_drivers() serial8250_console_write() spin_lock_irqsave(&port->lock) ** DEADLOCK ** The 8250_dw i/o accessors try to write a console error message if the LCR workaround was unsuccessful. When the port->lock is already held (eg., when called from serial8250_set_termios()), this deadlocks. Make the error message a FIXME until a general solution is devised. Cc: Tim Kryger Reported-by: Zhang Zhen Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_dw.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 2ab229ddee38..6ae5b8560e4d 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -119,7 +119,10 @@ static void dw8250_serial_out(struct uart_port *p, int offset, int value) dw8250_force_idle(p); writeb(value, p->membase + (UART_LCR << p->regshift)); } - dev_err(p->dev, "Couldn't set LCR to %d\n", value); + /* + * FIXME: this deadlocks if port->lock is already held + * dev_err(p->dev, "Couldn't set LCR to %d\n", value); + */ } } @@ -163,7 +166,10 @@ static void dw8250_serial_outq(struct uart_port *p, int offset, int value) __raw_writeq(value & 0xff, p->membase + (UART_LCR << p->regshift)); } - dev_err(p->dev, "Couldn't set LCR to %d\n", value); + /* + * FIXME: this deadlocks if port->lock is already held + * dev_err(p->dev, "Couldn't set LCR to %d\n", value); + */ } } #endif /* CONFIG_64BIT */ @@ -187,7 +193,10 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value) dw8250_force_idle(p); writel(value, p->membase + (UART_LCR << p->regshift)); } - dev_err(p->dev, "Couldn't set LCR to %d\n", value); + /* + * FIXME: this deadlocks if port->lock is already held + * dev_err(p->dev, "Couldn't set LCR to %d\n", value); + */ } } -- cgit v1.2.3 From e91d863d1aaeda0349aed42dfbd75c98e042a2c9 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Fri, 13 Mar 2015 12:38:51 +0100 Subject: serial: samsung: Clear operation mode on UART shutdown Exynos serial ports operate either in a DMA-based or interrupt-based modes. In DMA-based mode, the UART generates a transfer data request and a Transmission (Tx) interrupt in interrupt-based mode. The Tx IRQ is only unmasked in interrupt-based mode and it was done in s3c24xx_serial_start_tx(). Commit ba019a3e2ad5 ("serial: samsung: remove redundant interrupt enabling") removed the IRQ enable on that function since it is enabled when the mode is set in enable_tx_pio(). The problem is that enable_tx_pio() is only called if the port mode has not been set before but the mode was not cleared on .shutdown(). So if the UART was shutdown and then started up again, the mode set will remain and the Tx IRQ won't be unmasked. This caused a hang on at least Exynos5250, Exynos5420 and Exynos5800 when the system is rebooted or powered off. Fixes: ba019a3e2ad5 ("serial: samsung: remove redundant interrupt enabling") Signed-off-by: Javier Martinez Canillas Reviewed-by: Sylwester Nawrocki Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/samsung.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index af821a908720..cf08876922f1 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -963,6 +963,7 @@ static void s3c24xx_serial_shutdown(struct uart_port *port) free_irq(ourport->tx_irq, ourport); tx_enabled(port) = 0; ourport->tx_claimed = 0; + ourport->tx_mode = 0; } if (ourport->rx_claimed) { -- cgit v1.2.3 From 4e8f245937091b2c9eebf3d4909c9ceda4f0a78e Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Fri, 13 Mar 2015 14:51:50 +0100 Subject: tty: serial: fsl_lpuart: specify transmit FIFO size Specify transmit FIFO size which might be different depending on LPUART instance. This makes sure uart_wait_until_sent in serial core getting called, which in turn waits and checks if the FIFO is really empty on shutdown by using the tx_empty callback. Without the call of this callback, the last several characters might not yet be transmitted when closing the serial port. This can be reproduced by simply using echo and redirect the output to a ttyLP device. Signed-off-by: Stefan Agner Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index b1893f3f88f1..7ec911000ec2 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1076,6 +1076,8 @@ static int lpuart_startup(struct uart_port *port) sport->txfifo_size = 0x1 << (((temp >> UARTPFIFO_TXSIZE_OFF) & UARTPFIFO_FIFOSIZE_MASK) + 1); + sport->port.fifosize = sport->txfifo_size; + sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) & UARTPFIFO_FIFOSIZE_MASK) + 1); -- cgit v1.2.3 From 8e4934c6d6c659e22b1b746af4196683e77ce6ca Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Fri, 13 Mar 2015 14:51:51 +0100 Subject: tty: serial: fsl_lpuart: clear receive flag on FIFO flush When the receiver was enabled during startup, a character could have been in the FIFO when the UART get initially used. The driver configures the (receive) watermark level, and flushes the FIFO. However, the receive flag (RDRF) could still be set at that stage (as mentioned in the register description of UARTx_RWFIFO). This leads to an interrupt which won't be handled properly in interrupt mode: The receive interrupt function lpuart_rxint checks the FIFO count, which is 0 at that point (due to the flush during initialization). The problem does not manifest when using DMA to receive characters. Fix this situation by explicitly read the status register, which leads to clearing of the RDRF flag. Due to the flush just after the status flag read, a explicit data read is not to required. Signed-off-by: Stefan Agner Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 7ec911000ec2..3ad1458bfeb0 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -921,6 +921,9 @@ static void lpuart_setup_watermark(struct lpuart_port *sport) writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE, sport->port.membase + UARTPFIFO); + /* explicitly clear RDRF */ + readb(sport->port.membase + UARTSR1); + /* flush Tx and Rx FIFO */ writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); -- cgit v1.2.3