video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display()

Make ssd1307fb_update_display() return an error code, so callers that
can handle failures can propagate it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-2-geert@linux-m68k.org

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index eda448b..e6b6263 100644 (file)
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -152,17 +152,17 @@ static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
        return ret;
 }
 
-static void ssd1307fb_update_display(struct ssd1307fb_par *par)
+static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 {
        struct ssd1307fb_array *array;
        u8 *vmem = par->info->screen_buffer;
        unsigned int line_length = par->info->fix.line_length;
        unsigned int pages = DIV_ROUND_UP(par->height, 8);
-       int i, j, k;
+       int ret, i, j, k;
 
        array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA);
        if (!array)
-               return;
+               return -ENOMEM;
 
        /*
         * The screen is divided in pages, each having a height of 8
@@ -210,8 +210,9 @@ static void ssd1307fb_update_display(struct ssd1307fb_par *par)
                }
        }
 
-       ssd1307fb_write_array(par->client, array, par->width * pages);
+       ret = ssd1307fb_write_array(par->client, array, par->width * pages);
        kfree(array);
+       return ret;
 }
 
 
@@ -222,6 +223,7 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
        unsigned long total_size;
        unsigned long p = *ppos;
        void *dst;
+       int ret;
 
        total_size = info->fix.smem_len;
 
@@ -239,7 +241,9 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
        if (copy_from_user(dst, buf, count))
                return -EFAULT;
 
-       ssd1307fb_update_display(par);
+       ret = ssd1307fb_update_display(par);
+       if (ret < 0)
+               return ret;
 
        *ppos += count;
 
@@ -483,7 +487,9 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
                return ret;
 
        /* Clear the screen */
-       ssd1307fb_update_display(par);
+       ret = ssd1307fb_update_display(par);
+       if (ret < 0)
+               return ret;
 
        /* Turn on the display */
        ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);