Re: [PATCH v6 13/14] mtd: onenand: omap2: Configure driver from DT

[Aaro Koskinen <aaro.koskinen@xxxxxx>]

Hi,

On Sat, Dec 22, 2018 at 11:19:38AM +0100, Ladislav Michl wrote:
> Well, DT timings for onenand node seems to be copied over without actually
> verifying correctness. I do not know which chip comes with N950, so please
> verify timings in you DT according chip used. Idea is to use timings for
> slowest chip used and driver will ask for faster one if possible.

Hmm, right. I thought we had some dumped values in the DT, but apparently
wrong ones. What is the method for dumping the "right" values? If I just
enable GPMC debug with old kernel, it's dumping the DT entries twice,
but neither set works with the new kernel.

Then I tried the "before" values from the new kernel, and they seem to
work (patch below)...

A.

diff --git a/arch/arm/boot/dts/omap3-n950-n9.dtsi b/arch/arm/boot/dts/omap3-n950-n9.dtsi
index 0d9b85317529..6323a6d21e4a 100644
--- a/arch/arm/boot/dts/omap3-n950-n9.dtsi
+++ b/arch/arm/boot/dts/omap3-n950-n9.dtsi
@@ -379,25 +379,25 @@
 		gpmc,device-width = <2>;
 		gpmc,mux-add-data = <2>;
 		gpmc,cs-on-ns = <0>;
-		gpmc,cs-rd-off-ns = <87>;
-		gpmc,cs-wr-off-ns = <87>;
+		gpmc,cs-rd-off-ns = <122>;
+		gpmc,cs-wr-off-ns = <122>;
 		gpmc,adv-on-ns = <0>;
-		gpmc,adv-rd-off-ns = <10>;
-		gpmc,adv-wr-off-ns = <10>;
-		gpmc,oe-on-ns = <15>;
-		gpmc,oe-off-ns = <87>;
+		gpmc,adv-rd-off-ns = <15>;
+		gpmc,adv-wr-off-ns = <15>;
+		gpmc,oe-on-ns = <20>;
+		gpmc,oe-off-ns = <122>;
 		gpmc,we-on-ns = <0>;
-		gpmc,we-off-ns = <87>;
-		gpmc,rd-cycle-ns = <112>;
-		gpmc,wr-cycle-ns = <112>;
-		gpmc,access-ns = <81>;
+		gpmc,we-off-ns = <122>;
+		gpmc,rd-cycle-ns = <148>;
+		gpmc,wr-cycle-ns = <148>;
+		gpmc,access-ns = <117>;
 		gpmc,page-burst-access-ns = <15>;
 		gpmc,bus-turnaround-ns = <0>;
 		gpmc,cycle2cycle-delay-ns = <0>;
 		gpmc,wait-monitoring-ns = <0>;
-		gpmc,clk-activation-ns = <5>;
-		gpmc,wr-data-mux-bus-ns = <30>;
-		gpmc,wr-access-ns = <81>;
+		gpmc,clk-activation-ns = <10>;
+		gpmc,wr-data-mux-bus-ns = <40>;
+		gpmc,wr-access-ns = <117>;
 		gpmc,sync-clk-ps = <15000>;
 
 		/*

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