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iPod Classic: disable IRAM1

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On Classic, IRAM1 (second 128Kb of a total of 256KB available IRAM) is
slower than DRAM. Codecs that actually are using regions of IRAM1 runs
faster when DRAM is used, so IRAM1 is disabled and only IRAM0 remains
enabled: 48KB for core and 80KB for codecs/plugins.

The next test_codec results shows how decode time is decreased:

file           boosted     unboosted
*.ra           ~1.5%       ~0.5%
*.mpc          ~21%        ~4.5%
*.ogg          ~0.5%       ~0%
nero_he*.m4a   ~8%         ~1%
nero*.m4a      ~25%        ~7%
wmapro*.wma    ~4.5%       ~0%
wma*.wma       ~25%        ~7%

In addition there is a small power save when IRAM1 HW is disabled.

Change-Id: I102adee11458e82037f23076d5d5956e23235de8
This commit is contained in:
Cástor Muñoz 2017-01-13 20:51:07 +01:00 • committed by Franklin Wei
parent 8f38f85fbd
commit 7442742208
11 changed files with 25 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

2
firmware/target/arm/s5l8702/app.lds
View file

@ -19,7 +19,7 @@ STARTUP(target/arm/s5l8702/crt0.o)
#define DRAMSIZE (DRAM_SIZE - PLUGINSIZE - CODECSIZE - TTB_SIZE)
#define CODECORIG (ENDAUDIOADDR)
#define IRAMSIZE (56*1024) /* 256KB total - 56KB for core, 200KB for codecs */
#define IRAMSIZE (48*1024) /* 256KB total - 48KB for core, 200KB for codecs */
/* Where the codec buffer ends, and the plugin buffer starts */
#define ENDADDR (ENDAUDIOADDR + CODECSIZE)

2
firmware/target/arm/s5l8702/pcm-s5l8702.c
View file

@ -207,7 +207,6 @@ void pcm_dma_apply_settings(void)
void pcm_play_dma_init(void)
{
PWRCON(0) &= ~(1 << 4);
PWRCON(1) &= ~(1 << 7);
dmac_ch_init(&dma_play_ch, &dma_play_ch_cfg);
@ -406,7 +405,6 @@ void pcm_rec_dma_init(void)
if (pcm_rec_initialized)
return;
PWRCON(0) &= ~(1 << 4);
PWRCON(1) &= ~(1 << 7);
dmac_ch_init(&dma_rec_ch, &dma_rec_ch_cfg);

3
firmware/target/arm/s5l8702/system-s5l8702.c
View file

@ -199,6 +199,9 @@ enum {
void system_init(void)
{
/* disable IRAM1 (not used because it is slower than DRAM) */
clockgate_enable(CLOCKGATE_SM1, false);
clocking_init(clk_modes, 0);
#ifndef BOOTLOADER
gpio_preinit();