drm: mxsfb: Clear FIFO_CLEAR bit

[ 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: 45d59d7040 ("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@denx.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Marek Vasut 2021-06-21 00:49:46 +02:00 committed by AuxXxilium
parent b739e64a5e
commit 8114313bc7

View File

@ -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);