On 6/21/21 2:14 PM, Lucas Stach wrote:
[...]
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index 98d8ba0bae84..22cb749fc9bc 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -241,6 +241,9 @@ 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);
Do you really need those readbacks? As both writes are targeting the
same slave interface, the memory barrier in the clear write should push
the set write.
What would push the clear write then ? We can drop one of the readl()s,
but not the last one.
