From: Marek Vasut marex@denx.de
[ Upstream commit 5e23c98178eb1a2cdb7c4fee9a39baf8cabf282d ]
Make sure the FIFO_CLEAR bit is latched in when configuring the controller, so that the FIFO is really cleared. And then clear the FIFO_CLEAR bit, since it is not self-clearing.
Fixes: 45d59d704080 ("drm: Add new driver for MXSFB controller") Signed-off-by: Marek Vasut marex@denx.de Cc: Daniel Abrecht public@danielabrecht.ch Cc: Emil Velikov emil.l.velikov@gmail.com Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Stefan Agner stefan@agner.ch Reviewed-by: Jagan Teki jagan@amarulasolutions.com Tested-by: Jagan Teki jagan@amarulasolutions.com # i.Core MX8MM Acked-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Sam Ravnborg sam@ravnborg.org Link: https://patchwork.freedesktop.org/patch/msgid/20210620224946.189524-1-marex@... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/mxsfb/mxsfb_kms.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c index 5bcc06c1ac0b..54f905ac75c0 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c @@ -243,6 +243,9 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
/* Clear the FIFOs */ writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET); + readl(mxsfb->base + LCDC_CTRL1); + writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_CLR); + readl(mxsfb->base + LCDC_CTRL1);
if (mxsfb->devdata->has_overlay) writel(0, mxsfb->base + LCDC_AS_CTRL);