The patch titled
dz: fix locking issues
has been added to the -mm tree. Its filename is
dz-fix-locking-issues.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: dz: fix locking issues
From: "Maciej W. Rozycki" <macro@xxxxxxxxxxxxxx>
The ->start_tx(), ->stop_tx() and ->stop_rx() backends are called with the
port's lock already taken. Remove locking from within them and wrap around
calls as necessary.
Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
Cc: Jiri Slaby <jirislaby@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/serial/dz.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff -puN drivers/serial/dz.c~dz-fix-locking-issues drivers/serial/dz.c
--- a/drivers/serial/dz.c~dz-fix-locking-issues
+++ a/drivers/serial/dz.c
@@ -108,37 +108,28 @@ static void dz_stop_tx(struct uart_port
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line;
- unsigned long flags;
- spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp &= ~mask; /* clear the TX flag */
dz_out(dport, DZ_TCR, tmp);
- spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_start_tx(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line;
- unsigned long flags;
- spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp |= mask; /* set the TX flag */
dz_out(dport, DZ_TCR, tmp);
- spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_stop_rx(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
- unsigned long flags;
- spin_lock_irqsave(&dport->port.lock, flags);
dport->cflag &= ~DZ_CREAD;
dz_out(dport, DZ_LPR, dport->cflag | dport->port.line);
- spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_enable_ms(struct uart_port *port)
@@ -268,7 +259,9 @@ static inline void dz_transmit_chars(str
}
/* If nothing to do or stopped or hardware stopped. */
if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
+ spin_lock(&dport->port.lock);
dz_stop_tx(&dport->port);
+ spin_unlock(&dport->port.lock);
return;
}
@@ -285,8 +278,11 @@ static inline void dz_transmit_chars(str
uart_write_wakeup(&dport->port);
/* Are we are done. */
- if (uart_circ_empty(xmit))
+ if (uart_circ_empty(xmit)) {
+ spin_lock(&dport->port.lock);
dz_stop_tx(&dport->port);
+ spin_unlock(&dport->port.lock);
+ }
}
/*
@@ -417,7 +413,12 @@ static int dz_startup(struct uart_port *
*/
static void dz_shutdown(struct uart_port *uport)
{
- dz_stop_tx(uport);
+ struct dz_port *dport = (struct dz_port *)uport;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dport->port.lock, flags);
+ dz_stop_tx(&dport->port);
+ spin_unlock_irqrestore(&dport->port.lock, flags);
}
/*
_
Patches currently in -mm which might be from macro@xxxxxxxxxxxxxx are
origin.patch
kernel-printkc-concerns-about-the-console-handover.patch
dzh-remove-useless-unused-module-junk.patch
dz-always-check-if-it-is-safe-to-console_putchar.patch
dz-dont-panic-when-request_irq-fails.patch
dz-add-and-reorder-inclusions-remove-unneeded-ones.patch
dz-update-kconfig-description.patch
dz-rename-the-serial-console-structure.patch
dz-fix-locking-issues.patch
dz-handle-special-conditions-on-reception-correctly.patch
maintainers-add-self-for-the-dz-serial-driver.patch
-
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