| From 3352364bdf558c825f97ff96743d53c44385b50d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 30 Dec 2019 14:06:04 +0100 |
| Subject: drm/mipi_dbi: Fix off-by-one bugs in mipi_dbi_blank() |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Geert Uytterhoeven <geert+renesas@glider.be> |
| |
| [ Upstream commit 2ce18249af5a28031b3f909cfafccc88ea966c9d ] |
| |
| When configuring the frame memory window, the last column and row |
| numbers are written to the column resp. page address registers. These |
| numbers are thus one less than the actual window width resp. height. |
| |
| While this is handled correctly in mipi_dbi_fb_dirty() since commit |
| 03ceb1c8dfd1e293 ("drm/tinydrm: Fix setting of the column/page end |
| addresses."), it is not in mipi_dbi_blank(). The latter still forgets |
| to subtract one when calculating the most significant bytes of the |
| column and row numbers, thus programming wrong values when the display |
| width or height is a multiple of 256. |
| |
| Fixes: 02dd95fe31693626 ("drm/tinydrm: Add MIPI DBI support") |
| Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> |
| Signed-off-by: Noralf TrΓΈnnes <noralf@tronnes.org> |
| Link: https://patchwork.freedesktop.org/patch/msgid/20191230130604.31006-1-geert+renesas@glider.be |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/gpu/drm/drm_mipi_dbi.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c |
| index f8154316a3b0d..a05e64e3d80bb 100644 |
| --- a/drivers/gpu/drm/drm_mipi_dbi.c |
| +++ b/drivers/gpu/drm/drm_mipi_dbi.c |
| @@ -367,9 +367,9 @@ static void mipi_dbi_blank(struct mipi_dbi_dev *dbidev) |
| memset(dbidev->tx_buf, 0, len); |
| |
| mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 0, 0, |
| - (width >> 8) & 0xFF, (width - 1) & 0xFF); |
| + ((width - 1) >> 8) & 0xFF, (width - 1) & 0xFF); |
| mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 0, 0, |
| - (height >> 8) & 0xFF, (height - 1) & 0xFF); |
| + ((height - 1) >> 8) & 0xFF, (height - 1) & 0xFF); |
| mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, |
| (u8 *)dbidev->tx_buf, len); |
| |
| -- |
| 2.20.1 |
| |
