There is a driver that uses small buffer for the string, when we add a new one, we may avoid duplication and use one provided by the line display library. Allow user to skip buffer pointer when registering a device. Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/auxdisplay/line-display.c | 4 ++-- drivers/auxdisplay/line-display.h | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/auxdisplay/line-display.c b/drivers/auxdisplay/line-display.c index 75852ce6cc8d..d730cd0e1d03 100644 --- a/drivers/auxdisplay/line-display.c +++ b/drivers/auxdisplay/line-display.c @@ -330,8 +330,8 @@ int linedisp_register(struct linedisp *linedisp, struct device *parent, linedisp->dev.parent = parent; linedisp->dev.type = &linedisp_type; linedisp->ops = ops; - linedisp->buf = buf; - linedisp->num_chars = num_chars; + linedisp->buf = buf ? buf : linedisp->curr; + linedisp->num_chars = buf ? num_chars : min(num_chars, LINEDISP_DEFAULT_BUF_SZ); linedisp->scroll_rate = DEFAULT_SCROLL_RATE; err = ida_alloc(&linedisp_id, GFP_KERNEL); diff --git a/drivers/auxdisplay/line-display.h b/drivers/auxdisplay/line-display.h index 65d782111f53..4c354b8f376e 100644 --- a/drivers/auxdisplay/line-display.h +++ b/drivers/auxdisplay/line-display.h @@ -54,12 +54,15 @@ struct linedisp_ops { void (*update)(struct linedisp *linedisp); }; +#define LINEDISP_DEFAULT_BUF_SZ 8u + /** * struct linedisp - character line display private data structure * @dev: the line display device * @id: instance id of this display * @timer: timer used to implement scrolling * @ops: character line display operations + * @curr: fallback buffer for the string * @buf: pointer to the buffer for the string currently displayed * @message: the full message to display or scroll on the display * @num_chars: the number of characters that can be displayed @@ -73,6 +76,7 @@ struct linedisp { struct timer_list timer; const struct linedisp_ops *ops; struct linedisp_map *map; + char curr[LINEDISP_DEFAULT_BUF_SZ]; char *buf; char *message; unsigned int num_chars; -- 2.43.0.rc1.1.gbec44491f096