On 10/27/22 10:13, Marco Felsch wrote:
Hi,
[...]
diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c b/drivers/gpu/drm/mxsfb/lcdif_kms.c
index a5302006c02cd..aee7babb5fa5c 100644
--- a/drivers/gpu/drm/mxsfb/lcdif_kms.c
+++ b/drivers/gpu/drm/mxsfb/lcdif_kms.c
@@ -341,6 +341,18 @@ static void lcdif_enable_controller(struct lcdif_drm_private *lcdif)
reg = readl(lcdif->base + LCDC_V8_CTRLDESCL0_5);
reg |= CTRLDESCL0_5_EN;
writel(reg, lcdif->base + LCDC_V8_CTRLDESCL0_5);
+
+ /* Set FIFO Panic watermarks, low 1/3, high 2/3 . */
+ writel(FIELD_PREP(PANIC0_THRES_LOW_MASK, 1 * PANIC0_THRES_RANGE / 3) |
+ FIELD_PREP(PANIC0_THRES_HIGH_MASK, 2 * PANIC0_THRES_RANGE / 3),
+ lcdif->base + LCDC_V8_PANIC0_THRES);
+
+ /*
+ * Enable FIFO Panic, this does not generate interrupt, but
+ * boosts NoC priority based on FIFO Panic watermarks.
+ */
+ writel(INT_ENABLE_D1_PLANE_PANIC_EN,
+ lcdif->base + LCDC_V8_INT_ENABLE_D1);
Out of curiosity since we have a patch doing the exact same thing but
didn't saw any improvements. Is there a reason why you enabled it here?
It seems like the right thing to do here, when enabling the controller.
We did this during lcdif_rpm_resume(). But as I said with a 1080P
display we still saw the flickering, it disappeared first after rising
the burst-size.
That's what the NXP downstream driver does too, isn't it ? That seems
like the wrong place to me.
