On 12/04/2014 03:04 PM, Tony Lindgren wrote:
> Commit f4d809ec55b6 ("ARM: dts: Fix gpmc timings for omap 2430sdp")
> added GPMC timings for 2430sdp. This however broke the Ethernet
> for some versions of u-boot using a different L3 clock frequency:
>
> set_gpmc_timing_reg: GPMC error! CS5: cs_rd_off: 233 ns, 39 ticks > 31
> omap-gpmc 6e000000.gpmc: failed to set gpmc timings for: ethernet
>
> This is because the smsc91x timings from 1.1.4 u-boot overflow the
> GPMC registers when booted with 1.1.3 version of u-boot.
>
> Let's fix this issue by using the better timings from u-boot 1.1.3
> as they also work on 1.1.4 and are faster.
>
> Note that so far the attempts over the years to calculate the GPMC
> timings on the SDP boards have failed probably because of the
> unknown latencies added by the FPGA on the debug boards.
>
> Reported-by: Nishanth Menon <nm@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>
> --- a/arch/arm/boot/dts/omap2430-sdp.dts
> +++ b/arch/arm/boot/dts/omap2430-sdp.dts
> @@ -48,22 +48,22 @@
> gpmc,device-width = <1>;
> gpmc,cycle2cycle-samecsen = <1>;
> gpmc,cycle2cycle-diffcsen = <1>;
> - gpmc,cs-on-ns = <7>;
> - gpmc,cs-rd-off-ns = <233>;
> - gpmc,cs-wr-off-ns = <233>;
> - gpmc,adv-on-ns = <22>;
> - gpmc,adv-rd-off-ns = <60>;
> - gpmc,adv-wr-off-ns = <60>;
> - gpmc,oe-on-ns = <67>;
> - gpmc,oe-off-ns = <210>;
> - gpmc,we-on-ns = <67>;
> - gpmc,we-off-ns = <210>;
> - gpmc,rd-cycle-ns = <233>;
> - gpmc,wr-cycle-ns = <233>;
> - gpmc,access-ns = <233>;
> - gpmc,page-burst-access-ns = <30>;
> - gpmc,bus-turnaround-ns = <30>;
> - gpmc,cycle2cycle-delay-ns = <30>;
> + gpmc,cs-on-ns = <6>;
> + gpmc,cs-rd-off-ns = <187>;
> + gpmc,cs-wr-off-ns = <187>;
> + gpmc,adv-on-ns = <18>;
> + gpmc,adv-rd-off-ns = <48>;
> + gpmc,adv-wr-off-ns = <48>;
> + gpmc,oe-on-ns = <60>;
> + gpmc,oe-off-ns = <169>;
> + gpmc,we-on-ns = <66>;
> + gpmc,we-off-ns = <169>;
> + gpmc,rd-cycle-ns = <187>;
> + gpmc,wr-cycle-ns = <187>;
> + gpmc,access-ns = <187>;
> + gpmc,page-burst-access-ns = <24>;
> + gpmc,bus-turnaround-ns = <24>;
> + gpmc,cycle2cycle-delay-ns = <24>;
> gpmc,wait-monitoring-ns = <0>;
> gpmc,clk-activation-ns = <0>;
> gpmc,wr-data-mux-bus-ns = <0>;
>
Before (with gpmc debug): http://slexy.org/raw/s2bbhWNGxU
After:
http://slexy.org/raw/s20lY1YW65
Acked-by: Nishanth Menon <nm@xxxxxx>
--
Regards,
Nishanth Menon
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