[coreboot-gerrit] Change in coreboot[master]: sc7180: Fix prefill requirement and correct the fetch start check

[Ravi kumar (Code Review)]

Ravi kumar has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/47067 )

Change subject: sc7180: Fix prefill requirement and correct the fetch start check
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sc7180: Fix prefill requirement and correct the fetch start check

With Innolux panel timings, the fetch_start has evaluated to be more than
v_total which is invalid. Add a check to accommodate the extra h_total addition
in fetch_start calculation. Secondly, made the prefill line requirement
same as Kernel driver.

Change-Id: If7624c0b28421759fdf47dd92f23214a78058199
Signed-off-by: Vinod Polimera 
---
M src/soc/qualcomm/sc7180/display/mdss.c
1 file changed, 4 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/67/47067/1

diff --git a/src/soc/qualcomm/sc7180/display/mdss.c b/src/soc/qualcomm/sc7180/display/mdss.c
index 2d6bf6f..ce46e8e 100644
--- a/src/soc/qualcomm/sc7180/display/mdss.c
+++ b/src/soc/qualcomm/sc7180/display/mdss.c
@@ -6,7 +6,7 @@
 #include <edid.h>
 #include <soc/display/mdssreg.h>

-#define MDSS_MDP_MAX_PREFILL_FETCH 25
+#define MDSS_MDP_MAX_PREFILL_FETCH 24

static void mdss_source_pipe_config(struct edid *edid)
 {
@@ -91,9 +91,10 @@
    /*
     * MDP programmable fetch is for MDP with rev >= 1.05.
     * Programmable fetch is not needed if vertical back porch
-	 * plus vertical puls width is >= 25.
+	 * plus vertical pulse width plus extra line for the extra h_total
+	 * added during fetch start is >= 24.
     */
-	if ((edid->mode.vbl - edid->mode.vso) >= MDSS_MDP_MAX_PREFILL_FETCH)
+	if ((edid->mode.vbl - edid->mode.vso + 1) >= MDSS_MDP_MAX_PREFILL_FETCH)
    	return;

/*