3.0-stable patches

added patches:
	serial-mxs-auart-fix-race-condition-in-interrupt-handler.patch
	serial-mxs-auart-increase-time-to-wait-for-transmitter-to-become-idle.patch

diff --git a/queue-3.0/serial-mxs-auart-fix-race-condition-in-interrupt-handler.patch b/queue-3.0/serial-mxs-auart-fix-race-condition-in-interrupt-handler.patch
new file mode 100644 (file)
index 0000000..f6f6d50
--- /dev/null
+++ b/queue-3.0/serial-mxs-auart-fix-race-condition-in-interrupt-handler.patch
@@ -0,0 +1,60 @@
+From d970d7fe65adff5efe75b4a73c4ffc9be57089f7 Mon Sep 17 00:00:00 2001
+From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+Date: Thu, 4 Jul 2013 11:28:51 +0200
+Subject: serial/mxs-auart: fix race condition in interrupt handler
+
+From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+
+commit d970d7fe65adff5efe75b4a73c4ffc9be57089f7 upstream.
+
+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.
+
+Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/tty/serial/mxs-auart.c |   17 +++++++++--------
+ 1 file changed, 9 insertions(+), 8 deletions(-)
+
+--- a/drivers/tty/serial/mxs-auart.c
++++ b/drivers/tty/serial/mxs-auart.c
+@@ -374,11 +374,18 @@ static void mxs_auart_settermios(struct
+ 
+ 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);
+@@ -397,12 +404,6 @@ static irqreturn_t mxs_auart_irq_handle(
+               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;
+ }
+ 

diff --git a/queue-3.0/serial-mxs-auart-increase-time-to-wait-for-transmitter-to-become-idle.patch b/queue-3.0/serial-mxs-auart-increase-time-to-wait-for-transmitter-to-become-idle.patch
new file mode 100644 (file)
index 0000000..67cd199
--- /dev/null
+++ b/queue-3.0/serial-mxs-auart-increase-time-to-wait-for-transmitter-to-become-idle.patch
@@ -0,0 +1,71 @@
+From 079a036f4283e2b0e5c26080b8c5112bc0cc1831 Mon Sep 17 00:00:00 2001
+From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+Date: Fri, 28 Jun 2013 11:49:41 +0200
+Subject: serial/mxs-auart: increase time to wait for transmitter to become idle
+
+From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+
+commit 079a036f4283e2b0e5c26080b8c5112bc0cc1831 upstream.
+
+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.
+
+Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/tty/serial/mxs-auart.c |   21 +++++++++++++--------
+ 1 file changed, 13 insertions(+), 8 deletions(-)
+
+--- a/drivers/tty/serial/mxs-auart.c
++++ b/drivers/tty/serial/mxs-auart.c
+@@ -543,7 +543,7 @@ auart_console_write(struct console *co,
+       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;
+@@ -564,18 +564,23 @@ auart_console_write(struct console *co,
+ 
+       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);
+ }

diff --git a/queue-3.0/series b/queue-3.0/series
new file mode 100644 (file)
index 0000000..a89f82e
--- /dev/null
+++ b/queue-3.0/series
@@ -0,0 +1,2 @@
+serial-mxs-auart-fix-race-condition-in-interrupt-handler.patch
+serial-mxs-auart-increase-time-to-wait-for-transmitter-to-become-idle.patch