linux-*: Add patch to resolve Zynq UART lockup issue

* The xuartps/cdns_uart driver has a hang condition during the boot of
  the kernel. The lock-up itself occurs during the set_termios call when
  there is data received in the RX FIFO before the first setup of the
  console device.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>

9 files changed, 154 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-xlnx/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch b/recipes-kernel/linux/linux-xlnx/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
new file mode 100644
index 00000000..4ecd4e48
--- /dev/null
+++ b/recipes-kernel/linux/linux-xlnx/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
@@ -0,0 +1,33 @@
+From c2a532266240230c5b49e56f1035e9ba27a61d96 Mon Sep 17 00:00:00 2001
+From: Nathan Rossi <nathan.rossi@xilinx.com>
+Date: Mon, 24 Nov 2014 15:11:43 +1000
+Subject: [PATCH] tty: xuartps: Fix RX hang, and TX corruption in set_termios
+
+Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
+---
+ drivers/tty/serial/xilinx_uartps.c | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
+index faf2d90..7c842f2 100644
+--- a/drivers/tty/serial/xilinx_uartps.c
++++ b/drivers/tty/serial/xilinx_uartps.c
+@@ -642,10 +642,11 @@ static void xuartps_set_termios(struct uart_port *port,
+ 
+        spin_lock_irqsave(&port->lock, flags);
+ 
+-       /* Empty the receive FIFO 1st before making changes */
+-       while ((xuartps_readl(XUARTPS_SR_OFFSET) &
+-                XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY)
+-               xuartps_readl(XUARTPS_FIFO_OFFSET);
++       /* Wait for the transmit FIFO to empty before making changes */
++       if (!(xuartps_readl(XUARTPS_CR_OFFSET) & XUARTPS_CR_TX_DIS)) {
++               while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY))
++                       cpu_relax();
++       }
+ 
+        /* Disable the TX and RX to set baud rate */
+        xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
+-- 
+2.1.1
+
diff --git a/recipes-kernel/linux/linux-xlnx/3.14/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch b/recipes-kernel/linux/linux-xlnx/3.14/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
new file mode 100644
index 00000000..bafd4332
--- /dev/null
+++ b/recipes-kernel/linux/linux-xlnx/3.14/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
@@ -0,0 +1,32 @@
+From 397b08fb903994ccaa2d4d7f4cf578c9d3028463 Mon Sep 17 00:00:00 2001
+From: Nathan Rossi <nathan.rossi@xilinx.com>
+Date: Mon, 24 Nov 2014 15:11:43 +1000
+Subject: [PATCH] tty: xuartps: Fix RX hang, and TX corruption in set_termios
+
+Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
+---
+ drivers/tty/serial/xilinx_uartps.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
+index dbbc195..fcb1c50 100644
+--- a/drivers/tty/serial/xilinx_uartps.c
++++ b/drivers/tty/serial/xilinx_uartps.c
+@@ -648,10 +648,10 @@ static void xuartps_set_termios(struct uart_port *port,
+ 
+        spin_lock_irqsave(&port->lock, flags);
+ 
+-       /* Empty the receive FIFO 1st before making changes */
+-       while ((xuartps_readl(XUARTPS_SR_OFFSET) &
+-                XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
+-               xuartps_readl(XUARTPS_FIFO_OFFSET);
++       /* Wait for the transmit FIFO to empty before making changes */
++       if (!(xuartps_readl(XUARTPS_CR_OFFSET) & XUARTPS_CR_TX_DIS)) {
++               while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY))
++                       cpu_relax();
+        }
+ 
+        /* Disable the TX and RX to set baud rate */
+-- 
+2.1.1
+
diff --git a/recipes-kernel/linux/linux-xlnx/3.17/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch b/recipes-kernel/linux/linux-xlnx/3.17/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
new file mode 100644
index 00000000..4ac6624d
--- /dev/null
+++ b/recipes-kernel/linux/linux-xlnx/3.17/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
@@ -0,0 +1,34 @@
+From c3181f01d21953bff9971e141a193c445099e90f Mon Sep 17 00:00:00 2001
+From: Nathan Rossi <nathan.rossi@xilinx.com>
+Date: Mon, 24 Nov 2014 15:11:43 +1000
+Subject: [PATCH] tty: xuartps: Fix RX hang, and TX corruption in set_termios
+
+Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
+---
+ drivers/tty/serial/xilinx_uartps.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
+index 7f8027f..74dd5c9 100644
+--- a/drivers/tty/serial/xilinx_uartps.c
++++ b/drivers/tty/serial/xilinx_uartps.c
+@@ -628,10 +628,12 @@ static void cdns_uart_set_termios(struct uart_port *port,
+ 
+        spin_lock_irqsave(&port->lock, flags);
+ 
+-       /* Empty the receive FIFO 1st before making changes */
+-       while ((cdns_uart_readl(CDNS_UART_SR_OFFSET) &
+-                CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) {
+-               cdns_uart_readl(CDNS_UART_FIFO_OFFSET);
++       /* Wait for the transmit FIFO to empty before making changes */
++       if (!(cdns_uart_readl(CDNS_UART_CR_OFFSET) & CDNS_UART_CR_TX_DIS)) {
++               while (!(cdns_uart_readl(CDNS_UART_SR_OFFSET) &
++                               CDNS_UART_SR_TXEMPTY)) {
++                       cpu_relax();
++               }
+        }
+ 
+        /* Disable the TX and RX to set baud rate */
+-- 
+2.1.1
+
diff --git a/recipes-kernel/linux/linux-xlnx_3.10.bb b/recipes-kernel/linux/linux-xlnx_3.10.bb
index 8edd4d71..d32c4241 100644
--- a/recipes-kernel/linux/linux-xlnx_3.10.bb
+++ b/recipes-kernel/linux/linux-xlnx_3.10.bb
@@ -9,3 +9,8 @@ include linux-xlnx.inc
 # The MACB driver is non-functional in the 3.10 kernel
 KERNEL_FEATURES_append_zynq += "features/xilinx/disable-macb.scc"
 
+FILESEXTRAPATHS_prepend := "${THISDIR}/linux-xlnx/3.10:"
+SRC_URI_append += " \
+                file://tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch \
+                "
+
diff --git a/recipes-kernel/linux/linux-xlnx_3.14.bb b/recipes-kernel/linux/linux-xlnx_3.14.bb
index d33b3a58..4a31ccff 100644
--- a/recipes-kernel/linux/linux-xlnx_3.14.bb
+++ b/recipes-kernel/linux/linux-xlnx_3.14.bb
@@ -8,4 +8,6 @@ include linux-xlnx.inc
 FILESEXTRAPATHS_prepend := "${THISDIR}/linux-xlnx/3.14:"
 SRC_URI_append += " \
                 file://usb-host-zynq-dr-of-PHY-reset-during-probe.patch \
+                file://tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch \
                 "
+
diff --git a/recipes-kernel/linux/linux-yocto/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch b/recipes-kernel/linux/linux-yocto/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
new file mode 100644
index 00000000..ea6bbe6b
--- /dev/null
+++ b/recipes-kernel/linux/linux-yocto/3.10/tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch
@@ -0,0 +1,34 @@
+From 4cbf3473ca25ac47d2d1e43113afce961d057b87 Mon Sep 17 00:00:00 2001
+From: Nathan Rossi <nathan.rossi@xilinx.com>
+Date: Mon, 24 Nov 2014 15:11:43 +1000
+Subject: [PATCH] tty: xuartps: Fix RX hang, and TX corruption in set_termios
+
+Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
+---
+ drivers/tty/serial/xilinx_uartps.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
+index e46e9f3..eb00754 100644
+--- a/drivers/tty/serial/xilinx_uartps.c
++++ b/drivers/tty/serial/xilinx_uartps.c
+@@ -646,10 +646,12 @@ static void xuartps_set_termios(struct uart_port *port,
+ 
+        spin_lock_irqsave(&port->lock, flags);
+ 
+-       /* Empty the receive FIFO 1st before making changes */
+-       while ((xuartps_readl(XUARTPS_SR_OFFSET) &
+-                XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
+-               xuartps_readl(XUARTPS_FIFO_OFFSET);
++       /* Wait for the transmit FIFO to empty before making changes */
++       if (!(xuartps_readl(XUARTPS_CR_OFFSET) & XUARTPS_CR_TX_DIS)) {
++               while (!(xuartps_readl(XUARTPS_SR_OFFSET) &
++                               XUARTPS_SR_TXEMPTY)) {
++                       cpu_relax();
++               }
+        }
+ 
+        /* Disable the TX and RX to set baud rate */
+-- 
+2.1.1
+
diff --git a/recipes-kernel/linux/linux-yocto_3.10.bbappend b/recipes-kernel/linux/linux-yocto_3.10.bbappend
index 5bc61056..1ddb2978 100644
--- a/recipes-kernel/linux/linux-yocto_3.10.bbappend
+++ b/recipes-kernel/linux/linux-yocto_3.10.bbappend
@@ -12,3 +12,7 @@ SRC_URI_append_microblaze += " \
                 file://7f15a256b556bf26780d7a0bd03c88914a852022.patch \
                 file://99399545d62533b4ae742190b5c6b11f7a5826d9.patch \
                 "
+SRC_URI_append_zynq += " \
+                file://tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch \
+                "
+
diff --git a/recipes-kernel/linux/linux-yocto_3.14.bbappend b/recipes-kernel/linux/linux-yocto_3.14.bbappend
index 651e0d72..944ff63b 100644
--- a/recipes-kernel/linux/linux-yocto_3.14.bbappend
+++ b/recipes-kernel/linux/linux-yocto_3.14.bbappend
@@ -2,3 +2,8 @@
 require linux-xilinx-configs.inc
 require linux-xilinx-machines.inc
 
+FILESEXTRAPATHS_prepend := "${THISDIR}/linux-xlnx/3.14:"
+SRC_URI_append_zynq += " \
+                file://tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch \
+                "
+
diff --git a/recipes-kernel/linux/linux-yocto_3.17.bbappend b/recipes-kernel/linux/linux-yocto_3.17.bbappend
index 651e0d72..f62d2ddc 100644
--- a/recipes-kernel/linux/linux-yocto_3.17.bbappend
+++ b/recipes-kernel/linux/linux-yocto_3.17.bbappend
@@ -2,3 +2,8 @@
 require linux-xilinx-configs.inc
 require linux-xilinx-machines.inc
 
+FILESEXTRAPATHS_prepend := "${THISDIR}/linux-xlnx/3.17:"
+SRC_URI_append_zynq += " \
+                file://tty-xuartps-Fix-RX-hang-and-TX-corruption-in-set_termios.patch \
+                "
+