On Thu, Mar 19, 2015 at 4:56 PM, Daniel Mack zonque@gmail.com wrote:
On 03/19/2015 04:13 PM, Yegor Yefremov wrote:
Strange. Have tried with "nand read" command, but still the same result with and without CONFIG_NAND_OMAP_GPMC_PREFETCH :
[2.150655 0.001006] NAND read: device 0 offset 0x260000, size 0x1200000 [15.978943 13.828288] 18874368 bytes read: OK
What about adding some debug prints to the prefetch setup function and see if it is executed at all?
I2C: ready DRAM: 256 MiB NAND: prefetch enabled NAND: 256 MiB MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1 Using default environment
I've added "NAND: prefetch enabled" output for:
#ifdef CONFIG_NAND_OMAP_GPMC_PREFETCH else { printf("NAND: prefetch enabled\n"); nand->read_buf = omap_nand_read_prefetch8; } #else
I've also put printf() into omap_nand_read_prefetch8() just to make sure it is called - it was called.
Further ideas?
Daniel, do you have the numbers? Images size and load time? What can I expect?
I don't currently have the setup at hand, sorry. But the number I recall from an email conversation back then is: The time from power-on, loading SPL, loading U-Boot, leeching a 6MB uImage, jumping into it waiting for the console to start dumping the kernel boot messages was less than 5 seconds in total.
I Linux I had ti,nand-xfer-type = "polled";. After replacing it with ti,nand-xfer-type = "prefetch-polled"; I now get
# dd if=/dev/mtdblock5 of=/dev/null bs=2M count=8 8+0 records in 8+0 records out 16777216 bytes (17 MB) copied, 2.58744 s, 6.5 MB/s
instead of:
# dd if=/dev/mtdblock5 of=/dev/null bs=2M count=8 8+0 records in 8+0 records out 16777216 bytes (17 MB) copied, 6.05157 s, 2.8 MB/s
Do I see it right, that DMA support is not implemented in am33xx.dtsi?
Yegor