From: Stefan Roese Date: Fri, 28 Jul 2006 16:34:58 +0000 (+0200) Subject: PPC440 DDR setup: Set SDRAM0_CFG0[PMU]=0 for best performance X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=a2c95a72247990dee9a03b26b4dc9fc0182c97ed;p=project%2Fbcm63xx%2Fu-boot.git PPC440 DDR setup: Set SDRAM0_CFG0[PMU]=0 for best performance AMCC suggested to set the PMU bit to 0 for best performace on the PPC440 DDR controller. Please see doc/README.440-DDR-performance for details. Patch by Stefan Roese, 28 Jul 2006 --- diff --git a/CHANGELOG b/CHANGELOG index 6b219d898e..df7470548f 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -2,6 +2,12 @@ Changes since U-Boot 1.1.4: ====================================================================== +* PPC440 DDR setup: Set SDRAM0_CFG0[PMU]=0 for best performance + AMCC suggested to set the PMU bit to 0 for best performace on + the PPC440 DDR controller. + Please see doc/README.440-DDR-performance for details. + Patch by Stefan Roese, 28 Jul 2006 + * AMCC bamboo (440EP) U-Boot image reduced to 384kbyte Please see doc/README.bamboo for details. Patch by Stefan Roese, 27 Jul 2006 diff --git a/board/amcc/yellowstone/yellowstone.c b/board/amcc/yellowstone/yellowstone.c index 86d0db751d..92dc9d4c02 100644 --- a/board/amcc/yellowstone/yellowstone.c +++ b/board/amcc/yellowstone/yellowstone.c @@ -313,13 +313,13 @@ void sdram_init(void) mtsdram(mem_tr0, 0x410a4012); /* ?? */ mtsdram(mem_rtr, 0x04080000); /* ?? */ mtsdram(mem_cfg1, 0x00000000); /* Self-refresh exit, disable PM */ - mtsdram(mem_cfg0, 0x34000000); /* Disable EEC */ + mtsdram(mem_cfg0, 0x30000000); /* Disable EEC */ udelay(400); /* Delay 200 usecs (min) */ /*-------------------------------------------------------------------- * Enable the controller, then wait for DCEN to complete *------------------------------------------------------------------*/ - mtsdram(mem_cfg0, 0x84000000); /* Enable */ + mtsdram(mem_cfg0, 0x80000000); /* Enable */ for (;;) { mfsdram(mem_mcsts, reg); diff --git a/board/amcc/yosemite/yosemite.c b/board/amcc/yosemite/yosemite.c index 674244155a..7f2e718203 100644 --- a/board/amcc/yosemite/yosemite.c +++ b/board/amcc/yosemite/yosemite.c @@ -309,13 +309,13 @@ void sdram_init(void) mtsdram(mem_tr0, 0x410a4012); /* ?? */ mtsdram(mem_rtr, 0x04080000); /* ?? */ mtsdram(mem_cfg1, 0x00000000); /* Self-refresh exit, disable PM */ - mtsdram(mem_cfg0, 0x34000000); /* Disable EEC */ + mtsdram(mem_cfg0, 0x30000000); /* Disable EEC */ udelay(400); /* Delay 200 usecs (min) */ /*-------------------------------------------------------------------- * Enable the controller, then wait for DCEN to complete *------------------------------------------------------------------*/ - mtsdram(mem_cfg0, 0x84000000); /* Enable */ + mtsdram(mem_cfg0, 0x80000000); /* Enable */ for (;;) { mfsdram(mem_mcsts, reg); diff --git a/cpu/ppc4xx/sdram.c b/cpu/ppc4xx/sdram.c index e31d59d80e..faeea5c91e 100644 --- a/cpu/ppc4xx/sdram.c +++ b/cpu/ppc4xx/sdram.c @@ -379,7 +379,7 @@ long int initdram(int board_type) /* * Enable the controller, then wait for DCEN to complete */ - mtsdram(mem_cfg0, 0x86000000); /* DCEN=1, PMUD=1, 64-bit */ + mtsdram(mem_cfg0, 0x82000000); /* DCEN=1, PMUD=0, 64-bit */ udelay(10000); if (get_ram_size(0, mb0cf[i].size) == mb0cf[i].size) { diff --git a/cpu/ppc4xx/spd_sdram.c b/cpu/ppc4xx/spd_sdram.c index c0a6933b84..c24456bea8 100644 --- a/cpu/ppc4xx/spd_sdram.c +++ b/cpu/ppc4xx/spd_sdram.c @@ -1007,9 +1007,9 @@ void program_cfg0(unsigned long* dimm_populated, } /* - * program Page Management Unit + * program Page Management Unit (0 == enabled) */ - cfg0 |= SDRAM_CFG0_PMUD; + cfg0 &= ~SDRAM_CFG0_PMUD; /* * program Memory Controller Options 0 diff --git a/doc/README.440-DDR-performance b/doc/README.440-DDR-performance new file mode 100644 index 0000000000..17bc74764b --- /dev/null +++ b/doc/README.440-DDR-performance @@ -0,0 +1,90 @@ +AMCC suggested to set the PMU bit to 0 for best performace on the +PPC440 DDR controller. The 440er common DDR setup files (sdram.c & +spd_sdram.c) are changed accordingly. So all 440er boards using +these setup routines will automatically receive this performance +increase. + +Please see below some benchmarks done by AMCC to demonstrate this +performance changes: + + +---------------------------------------- +SDRAM0_CFG0[PMU] = 1 (U-boot default for Bamboo, Yosemite and Yellowstone) +---------------------------------------- +Stream benchmark results +------------------------------------------------------------- +This system uses 8 bytes per DOUBLE PRECISION word. +------------------------------------------------------------- +Array size = 2000000, Offset = 0 +Total memory required = 45.8 MB. +Each test is run 10 times, but only +the *best* time for each is used. +------------------------------------------------------------- +Your clock granularity/precision appears to be 1 microseconds. +Each test below will take on the order of 112345 microseconds. + (= 112345 clock ticks) +Increase the size of the arrays if this shows that you are not getting +at least 20 clock ticks per test. +------------------------------------------------------------- +WARNING -- The above is only a rough guideline. +For best results, please be sure you know the precision of your system +timer. +------------------------------------------------------------- +Function Rate (MB/s) RMS time Min time Max time +Copy: 256.7683 0.1248 0.1246 0.1250 +Scale: 246.0157 0.1302 0.1301 0.1302 +Add: 255.0316 0.1883 0.1882 0.1885 +Triad: 253.1245 0.1897 0.1896 0.1899 + + +TTCP Benchmark Results +ttcp-t: socket +ttcp-t: connect +ttcp-t: buflen=8192, nbuf=2048, align=16384/0, port=5000 tcp -> +localhost +ttcp-t: 16777216 bytes in 0.28 real seconds = 454.29 Mbit/sec +++ +ttcp-t: 2048 I/O calls, msec/call = 0.14, calls/sec = 7268.57 +ttcp-t: 0.0user 0.1sys 0:00real 60% 0i+0d 0maxrss 0+2pf 3+1506csw + +---------------------------------------- +SDRAM0_CFG0[PMU] = 0 (Suggested modification) +Setting PMU = 0 provides a noticeable performance improvement *2% to +5% improvement in memory performance. +*Improves the Mbit/sec for TTCP benchmark by almost 76%. +---------------------------------------- +Stream benchmark results +------------------------------------------------------------- +This system uses 8 bytes per DOUBLE PRECISION word. +------------------------------------------------------------- +Array size = 2000000, Offset = 0 +Total memory required = 45.8 MB. +Each test is run 10 times, but only +the *best* time for each is used. +------------------------------------------------------------- +Your clock granularity/precision appears to be 1 microseconds. +Each test below will take on the order of 120066 microseconds. + (= 120066 clock ticks) +Increase the size of the arrays if this shows that you are not getting +at least 20 clock ticks per test. +------------------------------------------------------------- +WARNING -- The above is only a rough guideline. +For best results, please be sure you know the precision of your system +timer. +------------------------------------------------------------- +Function Rate (MB/s) RMS time Min time Max time +Copy: 262.5167 0.1221 0.1219 0.1223 +Scale: 258.4856 0.1238 0.1238 0.1240 +Add: 262.5404 0.1829 0.1828 0.1831 +Triad: 266.8594 0.1800 0.1799 0.1802 + +TTCP Benchmark Results +ttcp-t: socket +ttcp-t: connect +ttcp-t: buflen=8192, nbuf=2048, align=16384/0, port=5000 tcp -> +localhost +ttcp-t: 16777216 bytes in 0.16 real seconds = 804.06 Mbit/sec +++ +ttcp-t: 2048 I/O calls, msec/call = 0.08, calls/sec = 12864.89 +ttcp-t: 0.0user 0.0sys 0:00real 46% 0i+0d 0maxrss 0+2pf 120+1csw + + +2006-07-28, Stefan Roese