Merge tag 'tty-3.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are a few fixes for 3.13-rc5 that resolve a number of reported
tty and serial driver issues"
* tag 'tty-3.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: xuartps: Properly guard sysrq specific code
n_tty: Fix apparent order of echoed output
serial: 8250_dw: add new ACPI IDs
serial: 8250_dw: Fix LCR workaround regression
tty: Fix hang at ldsem_down_read()
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 268b627..34aacaa 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -93,6 +93,7 @@
size_t canon_head;
size_t echo_head;
size_t echo_commit;
+ size_t echo_mark;
DECLARE_BITMAP(char_map, 256);
/* private to n_tty_receive_overrun (single-threaded) */
@@ -336,6 +337,7 @@
{
ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0;
+ ldata->echo_mark = 0;
ldata->line_start = 0;
ldata->erasing = 0;
@@ -787,6 +789,7 @@
size_t head;
head = ldata->echo_head;
+ ldata->echo_mark = head;
old = ldata->echo_commit - ldata->echo_tail;
/* Process committed echoes if the accumulated # of bytes
@@ -811,10 +814,11 @@
size_t echoed;
if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
- ldata->echo_commit == ldata->echo_tail)
+ ldata->echo_mark == ldata->echo_tail)
return;
mutex_lock(&ldata->output_lock);
+ ldata->echo_commit = ldata->echo_mark;
echoed = __process_echoes(tty);
mutex_unlock(&ldata->output_lock);
@@ -822,6 +826,7 @@
tty->ops->flush_chars(tty);
}
+/* NB: echo_mark and echo_head should be equivalent here */
static void flush_echoes(struct tty_struct *tty)
{
struct n_tty_data *ldata = tty->disc_data;
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 4658e3e..06525f1 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -96,7 +96,8 @@
if (offset == UART_LCR) {
int tries = 1000;
while (tries--) {
- if (value == p->serial_in(p, UART_LCR))
+ unsigned int lcr = p->serial_in(p, UART_LCR);
+ if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
return;
dw8250_force_idle(p);
writeb(value, p->membase + (UART_LCR << p->regshift));
@@ -132,7 +133,8 @@
if (offset == UART_LCR) {
int tries = 1000;
while (tries--) {
- if (value == p->serial_in(p, UART_LCR))
+ unsigned int lcr = p->serial_in(p, UART_LCR);
+ if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
return;
dw8250_force_idle(p);
writel(value, p->membase + (UART_LCR << p->regshift));
@@ -455,6 +457,8 @@
static const struct acpi_device_id dw8250_acpi_match[] = {
{ "INT33C4", 0 },
{ "INT33C5", 0 },
+ { "INT3434", 0 },
+ { "INT3435", 0 },
{ "80860F0A", 0 },
{ },
};
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index e46e9f3..f619ad5 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -240,6 +240,7 @@
continue;
}
+#ifdef SUPPORT_SYSRQ
/*
* uart_handle_sysrq_char() doesn't work if
* spinlocked, for some reason
@@ -253,6 +254,7 @@
}
spin_lock(&port->lock);
}
+#endif
port->icount.rx++;
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 22fad8a..d8a55e8 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -86,11 +86,21 @@
return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
}
+/*
+ * ldsem_cmpxchg() updates @*old with the last-known sem->count value.
+ * Returns 1 if count was successfully changed; @*old will have @new value.
+ * Returns 0 if count was not changed; @*old will have most recent sem->count
+ */
static inline int ldsem_cmpxchg(long *old, long new, struct ld_semaphore *sem)
{
- long tmp = *old;
- *old = atomic_long_cmpxchg(&sem->count, *old, new);
- return *old == tmp;
+ long tmp = atomic_long_cmpxchg(&sem->count, *old, new);
+ if (tmp == *old) {
+ *old = new;
+ return 1;
+ } else {
+ *old = tmp;
+ return 0;
+ }
}
/*