@@ -355,11 +355,14 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
unsigned int width = drm_rect_width(rect);
unsigned int height = drm_rect_height(rect);
unsigned int line_length = DIV_ROUND_UP(width, 8);
- unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
+ unsigned int pages = DIV_ROUND_UP(height, 8);
+ struct drm_device *drm = &ssd130x->drm;
u32 array_idx = 0;
int ret, i, j, k;
u8 *data_array = NULL;
+ drm_WARN_ONCE(drm, y % 8 != 0, "y must be aligned to screen page\n");
+
data_array = kcalloc(width, pages, GFP_KERNEL);
if (!data_array)
return -ENOMEM;
@@ -401,13 +404,13 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
if (ret < 0)
goto out_free;
- for (i = y / 8; i < y / 8 + pages; i++) {
+ for (i = 0; i < pages; i++) {
int m = 8;
/* Last page may be partial */
- if (8 * (i + 1) > ssd130x->height)
+ if (8 * (y / 8 + i + 1) > ssd130x->height)
m = ssd130x->height % 8;
- for (j = x; j < x + width; j++) {
+ for (j = 0; j < width; j++) {
u8 data = 0;
for (k = 0; k < m; k++) {
@@ -454,6 +457,10 @@ static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_m
int ret = 0;
u8 *buf = NULL;
+ /* Align y to display page boundaries */
+ rect->y1 = round_down(rect->y1, 8);
+ rect->y2 = min_t(unsigned int, round_up(rect->y2, 8), ssd130x->height);
+
buf = kcalloc(fb->width, fb->height, GFP_KERNEL);
if (!buf)
return -ENOMEM;
The rectangle update functions ssd130x_fb_blit_rect() and ssd130x_update_rect() do not behave correctly when x1 != 0 or y1 != 0, or when y1 or y2 are not aligned to display page boundaries. E.g. when used as a text console, only the first line of text is shown on the display. 1. The buffer passed by ssd130x_fb_blit_rect() points to the first byte of monochrome bitmap data, and thus has its origin at (x1, y1), while ssd130x_update_rect() assumes it is at (0, 0). Fix ssd130x_update_rect() by changing the vertical and horizontal loop ranges, and adding the offsets only when needed. 2. In ssd130x_fb_blit_rect(), align y1 and y2 to the display page boundaries before doing the color conversion, so the full page is converted and updated. Remove the correction for an unaligned y1 from ssd130x_update_rect(), and add a check to make sure y1 is aligned. Fixes: a61732e808672cfa ("drm: Add driver for Solomon SSD130x OLED displays") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Javier Martinez Canillas <javierm@redhat.com> --- v2: - Add Acked-by. Note that instead of calling drm_fb_xrgb8888_to_mono() and transposing the bitmap, the image data could be converted to the transposed format directly. However, that would preclude exposing a monochrome format to userspace when a fourcc for such a monochrome format is introduced. --- drivers/gpu/drm/solomon/ssd130x.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)