TeamCanjica/Samsung_STE_Kernel — pull request #35 by ChronoMonochrome (2014-11-10 01:57:05+00:00)
Title: LiveOPP: add PLLDDR boost interface

Thanks @cocafe for idea and original patch.
I found way to overclock PLLDDR stably upto 975 MHz (on my codina).
To use this interface type command like that:
`echo 0x0005017f > /sys/kernel/liveopp/pllddr # 975 MHz`
Please note only values that starts with 0x0005.... are allowed.

I did some tests that confirmed better RAM performance:
Governor - performance, CPU 1200 MHz.

1) Memory speed benchmark:
a) 798 MHz

Reading speed in MBytes/second
Memory x[m]=x[m]+s*y[m] x[m]=x[m]+y[m]
Kbytes Dble Sngl Int Dble Sngl Int
16 1735 886 2381 2719 1360 2808
32 1586 819 1760 1991 1145 1953
64 1459 755 1279 1580 978 1410
128 1454 763 1223 1589 978 1345
256 1449 760 1183 1579 975 1298
512 940 697 934 1161 867 979
1024 480 443 463 489 457 490
4096 378 350 351 395 364 380
16384 402 353 397 389 382 391
65536 388 364 399 400 392 408

Total elapsed time: 12.9 seconds

b) 975 MHz

Reading speed in MBytes/second
Memory x[m]=x[m]+s*y[m] x[m]=x[m]+y[m]
Kbytes Dble Sngl Int Dble Sngl Int
16 1737 889 2449 2720 1365 2804
32 1600 824 1762 2006 1146 1958
64 1457 756 1286 1576 979 1404
128 1456 762 1224 1591 979 1347
256 1449 762 1193 1584 977 1292
512 1204 712 997 1274 901 1010
1024 573 524 575 538 540 582
4096 459 411 335 410 423 452
16384 455 434 458 482 435 471
65536 454 437 456 487 454 461

Total elapsed time: 12.0 seconds

2) random access benchmark:
a) 798 MHz

Mbytes/Second transferring 4 byte words:

Memory Serial......... Random.........
Kbytes Read Rd/Wrt Read Rd/Wrt
16 2788 3013 2787 3033
32 1879 1963 1745 2130
64 1103 1110 1029 1166
128 988 972 787 844
256 938 970 641 671
512 855 738 236 275
1024 627 415 110 89
4096 570 376 69 68
16384 573 367 59 58
65536 508 395 51 49

Total elapsed time: 12.2 seconds

b) 975 MHz

Mbytes/Second transferring 4 byte words:

Memory Serial......... Random.........
Kbytes Read Rd/Wrt Read Rd/Wrt
16 2779 3031 2785 3030
32 1878 1959 1734 2150
64 1101 1099 1034 1165
128 986 993 812 853
256 976 981 582 713
512 886 771 289 311
1024 657 541 129 125
4096 643 429 89 79
16384 643 467 72 69
65536 597 475 59 59

Total elapsed time: 11.5 seconds

mentioned benchmarks were found on
http://www.roylongbottom.org.uk/android%20benchmarks.htm

Signed-off-by: Shilin Victor