serdev: Restore serdev_device_write_buf for atomic context

Starting with commit 6fe729c4bdae ("serdev: Add serdev_device_write
subroutine") the function serdev_device_write_buf cannot be used in
atomic context anymore (mutex_lock is sleeping). So restore the old
behavior.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 6fe729c4bdae ("serdev: Add serdev_device_write subroutine")
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 433de5ea9b02f53386b9367e64ad880ac6795e07..f71b47334149ace03ff276e41d8ecfd2a7038c6e 100644 (file)
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -122,6 +122,18 @@ void serdev_device_write_wakeup(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
 
+int serdev_device_write_buf(struct serdev_device *serdev,
+                           const unsigned char *buf, size_t count)
+{
+       struct serdev_controller *ctrl = serdev->ctrl;
+
+       if (!ctrl || !ctrl->ops->write_buf)
+               return -EINVAL;
+
+       return ctrl->ops->write_buf(ctrl, buf, count);
+}
+EXPORT_SYMBOL_GPL(serdev_device_write_buf);
+
 int serdev_device_write(struct serdev_device *serdev,
                        const unsigned char *buf, size_t count,
                        unsigned long timeout)

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index cda76c6506ca411c42c5e1cdf6d287263d97dde6..e2a225bf716dbee64418e1c28fb25041cf5228c1 100644 (file)
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -195,6 +195,7 @@ int serdev_device_open(struct serdev_device *);
 void serdev_device_close(struct serdev_device *);
 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 void serdev_device_set_flow_control(struct serdev_device *, bool);
+int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
 void serdev_device_wait_until_sent(struct serdev_device *, long);
 int serdev_device_get_tiocm(struct serdev_device *);
 int serdev_device_set_tiocm(struct serdev_device *, int, int);
@@ -236,6 +237,12 @@ static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev
        return 0;
 }
 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
+static inline int serdev_device_write_buf(struct serdev_device *serdev,
+                                         const unsigned char *buf,
+                                         size_t count)
+{
+       return -ENODEV;
+}
 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
 {
@@ -312,11 +319,4 @@ static inline struct device *serdev_tty_port_register(struct tty_port *port,
 static inline void serdev_tty_port_unregister(struct tty_port *port) {}
 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 
-static inline int serdev_device_write_buf(struct serdev_device *serdev,
-                                         const unsigned char *data,
-                                         size_t count)
-{
-       return serdev_device_write(serdev, data, count, 0);
-}
-
 #endif /*_LINUX_SERDEV_H */