From: Marek Vasut marex@denx.de
[ Upstream commit c1cdee9b685a174fca849e1451c201a846a69318 ]
The RTNI field is multiplied by 16 and incremented by 512 before being used as the minimum number of pixel clock per horizontal line, hence it is necessary to subtract those 512 bytes from htotal and then divide the result by 16 before writing the value into the RTNI field. Fix the calculation.
Fixes: de2b4917843c ("drm/panel/panel-sitronix-st7701: Infer horizontal pixel count from TFT mode") Signed-off-by: Marek Vasut marex@denx.de Reviewed-by: Linus Walleij linus.walleij@linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20221012221159.88397-1-marex@d... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/panel/panel-sitronix-st7701.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7701.c b/drivers/gpu/drm/panel/panel-sitronix-st7701.c index c481daa4bbce..9578f461f5e4 100644 --- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c +++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c @@ -244,7 +244,7 @@ static void st7701_init_sequence(struct st7701 *st7701) DSI_CMD2_BK0_INVSEL_ONES_MASK | FIELD_PREP(DSI_CMD2_BK0_INVSEL_NLINV_MASK, desc->nlinv), FIELD_PREP(DSI_CMD2_BK0_INVSEL_RTNI_MASK, - DIV_ROUND_UP(mode->htotal, 16))); + (clamp((u32)mode->htotal, 512U, 1008U) - 512) / 16));
/* Command2, BK1 */ ST7701_DSI(st7701, DSI_CMD2BKX_SEL,