From d970d7fe65adff5efe75b4a73c4ffc9be57089f7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Thu, 4 Jul 2013 11:28:51 +0200 Subject: serial/mxs-auart: fix race condition in interrupt handler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The handler needs to ack the pending events before actually handling them. Otherwise a new event might come in after it it considered non-pending or handled and is acked then without being handled. So this event is only noticed when the next interrupt happens. Without this patch an i.MX28 based machine running an rt-patched kernel regularly hangs during boot. Cc: stable@vger.kernel.org # v2.6.39+ Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 4f5f161896a1..3de0fb2712f5 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -678,11 +678,18 @@ static void mxs_auart_settermios(struct uart_port *u, static irqreturn_t mxs_auart_irq_handle(int irq, void *context) { - u32 istatus, istat; + u32 istat; struct mxs_auart_port *s = context; u32 stat = readl(s->port.membase + AUART_STAT); - istatus = istat = readl(s->port.membase + AUART_INTR); + istat = readl(s->port.membase + AUART_INTR); + + /* ack irq */ + writel(istat & (AUART_INTR_RTIS + | AUART_INTR_TXIS + | AUART_INTR_RXIS + | AUART_INTR_CTSMIS), + s->port.membase + AUART_INTR_CLR); if (istat & AUART_INTR_CTSMIS) { uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS); @@ -702,12 +709,6 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context) istat &= ~AUART_INTR_TXIS; } - writel(istatus & (AUART_INTR_RTIS - | AUART_INTR_TXIS - | AUART_INTR_RXIS - | AUART_INTR_CTSMIS), - s->port.membase + AUART_INTR_CLR); - return IRQ_HANDLED; } -- cgit v1.2.2 From 079a036f4283e2b0e5c26080b8c5112bc0cc1831 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 28 Jun 2013 11:49:41 +0200 Subject: serial/mxs-auart: increase time to wait for transmitter to become idle MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Without this patch the driver waits ~1 ms for the UART to become idle. At 115200n8 this time is (theoretically) enough to transfer 11.5 characters (= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size of 16 characters the clock is gated too early. The problem is worse for lower baud rates. This only happens to really shut down the transmitter in the middle of a transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but was at least once (because the bootloader doesn't disable the transmitter). So increase the timeout to 20 ms which should be enough for 9600n8, too. Moreover skip gating the clock if the timeout is elapsed. Cc: stable@vger.kernel.org # v2.6.39+ Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 3de0fb2712f5..f85b8e6d0346 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -851,7 +851,7 @@ auart_console_write(struct console *co, const char *str, unsigned int count) struct mxs_auart_port *s; struct uart_port *port; unsigned int old_ctrl0, old_ctrl2; - unsigned int to = 1000; + unsigned int to = 20000; if (co->index >= MXS_AUART_PORTS || co->index < 0) return; @@ -872,18 +872,23 @@ auart_console_write(struct console *co, const char *str, unsigned int count) uart_console_write(port, str, count, mxs_auart_console_putchar); - /* - * Finally, wait for transmitter to become empty - * and restore the TCR - */ + /* Finally, wait for transmitter to become empty ... */ while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) { + udelay(1); if (!to--) break; - udelay(1); } - writel(old_ctrl0, port->membase + AUART_CTRL0); - writel(old_ctrl2, port->membase + AUART_CTRL2); + /* + * ... and restore the TCR if we waited long enough for the transmitter + * to be idle. This might keep the transmitter enabled although it is + * unused, but that is better than to disable it while it is still + * transmitting. + */ + if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) { + writel(old_ctrl0, port->membase + AUART_CTRL0); + writel(old_ctrl2, port->membase + AUART_CTRL2); + } clk_disable(s->clk); } -- cgit v1.2.2 From 1d9e689c934bd5ecb0f273c6c65e0655c5cfee5f Mon Sep 17 00:00:00 2001 From: Gianluca Anzolin Date: Thu, 25 Jul 2013 07:26:16 +0200 Subject: tty_port: Fix refcounting leak in tty_port_tty_hangup() The function tty_port_tty_hangup() could leak a reference to the tty_struct: struct tty_struct *tty = tty_port_tty_get(port); if (tty && (!check_clocal || !C_CLOCAL(tty))) { tty_hangup(tty); tty_kref_put(tty); } If tty != NULL and the second condition is false we never call tty_kref_put and the reference is leaked. Fix by always calling tty_kref_put() which accepts a NULL argument. The patch fixes a regression introduced by commit aa27a094. Acked-by: Gustavo Padovan Signed-off-by: Gianluca Anzolin Acked-by: Jiri Slaby Cc: stable # 3.10 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_port.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c index 121aeb9393e1..f597e88a705d 100644 --- a/drivers/tty/tty_port.c +++ b/drivers/tty/tty_port.c @@ -256,10 +256,9 @@ void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) { struct tty_struct *tty = tty_port_tty_get(port); - if (tty && (!check_clocal || !C_CLOCAL(tty))) { + if (tty && (!check_clocal || !C_CLOCAL(tty))) tty_hangup(tty); - tty_kref_put(tty); - } + tty_kref_put(tty); } EXPORT_SYMBOL_GPL(tty_port_tty_hangup); -- cgit v1.2.2 From d5a12ea7a9e58d9e5c19d25cb668aadb396423ec Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Sun, 21 Jul 2013 10:14:15 +0800 Subject: serial: arc_uart: Fix module alias Platform drivers use "platform:" prefix in module alias. Also use DRIVER_NAME in MODULE_ALIAS to make module autoloading work. Signed-off-by: Axel Lin Acked-by: Vineet Gupta Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/arc_uart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c index cbf1d155b7b2..22f280aa4f2c 100644 --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -773,6 +773,6 @@ module_init(arc_serial_init); module_exit(arc_serial_exit); MODULE_LICENSE("GPL"); -MODULE_ALIAS("plat-arcfpga/uart"); +MODULE_ALIAS("platform:" DRIVER_NAME); MODULE_AUTHOR("Vineet Gupta"); MODULE_DESCRIPTION("ARC(Synopsys) On-Chip(fpga) serial driver"); -- cgit v1.2.2 From dd5e6d6a3db09b16b7c222943977865eead88cc3 Mon Sep 17 00:00:00 2001 From: Thomas Bogendoerfer Date: Tue, 30 Jul 2013 02:02:16 +0200 Subject: parisc: Fix interrupt routing for C8000 serial ports We can't use dev->mod_index for selecting the interrupt routing entry, because it's not an index into interrupt routing table. It will be even wrong on a machine with 2 CPUs (4 cores). But all needed information is contained in the PAT entries for the serial ports. mod[0] contains the iosapic address and mod_info has some indications for the interrupt input (at least it looks like it). This patch implements the searching for the right iosapic and uses this interrupt input information. Signed-off-by: Thomas Bogendoerfer Cc: # 3.10 Signed-off-by: Helge Deller --- drivers/tty/serial/8250/8250_gsc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_gsc.c b/drivers/tty/serial/8250/8250_gsc.c index bb91b4713ebd..2e3ea1a70d7b 100644 --- a/drivers/tty/serial/8250/8250_gsc.c +++ b/drivers/tty/serial/8250/8250_gsc.c @@ -31,9 +31,8 @@ static int __init serial_init_chip(struct parisc_device *dev) int err; #ifdef CONFIG_64BIT - extern int iosapic_serial_irq(int cellnum); if (!dev->irq && (dev->id.sversion == 0xad)) - dev->irq = iosapic_serial_irq(dev->mod_index-1); + dev->irq = iosapic_serial_irq(dev); #endif if (!dev->irq) { -- cgit v1.2.2