diff options
| author | Rich Felker <dalias@libc.org> | 2016-01-08 23:33:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-07 09:56:43 +0300 |
| commit | 9e370d2c9f59a63dda0ced3ecd1b55498d97c449 (patch) | |
| tree | 12c0f8218b6e7f8c29648cc9ab2552be3e23a7bb | |
| parent | 7cdcc29e4919dc31f494eaf05e46005c28efe832 (diff) | |
| download | linux-9e370d2c9f59a63dda0ced3ecd1b55498d97c449.tar.xz | |
serial-uartlite: fix missing locking in isr
The uartlite driver suffers from missing/duplicate/corrupted character
data when the interrupt handler runs concurrently with access to the
device from another cpu. Take the port spinlock to exclude concurrent
access.
Signed-off-by: Rich Felker <dalias@libc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/uartlite.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c index c249aee887d2..ee2e8efdea4a 100644 --- a/drivers/tty/serial/uartlite.c +++ b/drivers/tty/serial/uartlite.c @@ -194,7 +194,9 @@ static irqreturn_t ulite_isr(int irq, void *dev_id) { struct uart_port *port = dev_id; int busy, n = 0; + unsigned long flags; + spin_lock_irqsave(&port->lock, flags); do { int stat = uart_in32(ULITE_STATUS, port); busy = ulite_receive(port, stat); @@ -202,6 +204,8 @@ static irqreturn_t ulite_isr(int irq, void *dev_id) n++; } while (busy); + spin_unlock_irqrestore(&port->lock, flags); + /* work done? */ if (n > 1) { tty_flip_buffer_push(&port->state->port); |