From 36d9579fed6c9429aa172f77bd28c58696ce8e2b Mon Sep 17 00:00:00 2001 From: Francesco Lavra Date: Tue, 10 Feb 2026 19:09:32 +0100 Subject: [PATCH] drm/solomon: Fix page start when updating rectangle in page addressing mode In page addressing mode, the pixel values of a dirty rectangle must be sent to the display controller one page at a time. The range of pages corresponding to a given rectangle is being incorrectly calculated as if the Y value of the top left coordinate of the rectangle was 0. This can result in rectangle updates being displayed on wrong parts of the screen. Fix the above issue by consolidating the start page calculation in a single place at the beginning of the update_rect function, and using the calculated value for all addressing modes. Fixes: b0daaa5cfaa5 ("drm/ssd130x: Support page addressing mode") Signed-off-by: Francesco Lavra Reviewed-by: Javier Martinez Canillas Link: https://patch.msgid.link/20260210180932.736502-1-flavra@baylibre.com Signed-off-by: Javier Martinez Canillas --- drivers/gpu/drm/solomon/ssd130x.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index 6ecf9e2ff61b..c77455b1834d 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -737,6 +737,7 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, unsigned int height = drm_rect_height(rect); unsigned int line_length = DIV_ROUND_UP(width, 8); unsigned int page_height = SSD130X_PAGE_HEIGHT; + u8 page_start = ssd130x->page_offset + y / page_height; unsigned int pages = DIV_ROUND_UP(height, page_height); struct drm_device *drm = &ssd130x->drm; u32 array_idx = 0; @@ -774,14 +775,11 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, */ if (!ssd130x->page_address_mode) { - u8 page_start; - /* Set address range for horizontal addressing mode */ ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width); if (ret < 0) return ret; - page_start = ssd130x->page_offset + y / page_height; ret = ssd130x_set_page_range(ssd130x, page_start, pages); if (ret < 0) return ret; @@ -813,7 +811,7 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, */ if (ssd130x->page_address_mode) { ret = ssd130x_set_page_pos(ssd130x, - ssd130x->page_offset + i, + page_start + i, ssd130x->col_offset + x); if (ret < 0) return ret;