7dbda25ecd
When running a NXP 4.1 kernel with U-Boot mainline on a mx6ul-evk, we observe a hang when going into the lowest operational point of cpufreq. This hang issue does not happen on the NXP U-Boot version. After comparing the SPL DDR initialization against the DCD table from NXP U-Boot, the key difference that causes the hang is the MDREF register setting: DATA 4 0x021B0020 0x00000800 ,which means: REF_SEL = 0 --> Periodic refresh cycle: 64kHz REFR = 1 ---> Refresh Rate - 2 refreshes So adjust the MDREF initialization for mx6ul_evk accordingly to fix the kernel hang issue at low bus frequency. Reported-by: Eric Nelson <eric@nelint.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Eric Nelson <eric@nelint.com> |
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| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| mx6ul_14x14_evk.c | ||
| README | ||
How to use U-Boot on Freescale MX6UL 14x14 EVK ----------------------------------------------- - Build U-Boot for MX6UL 14x14 EVK: $ make mrproper $ make mx6ul_14x14_evk_defconfig $ make This will generate the SPL image called SPL and the u-boot.img. - Flash the SPL image into the micro SD card: sudo dd if=SPL of=/dev/mmcblk0 bs=1k seek=1; sync - Flash the u-boot.img image into the micro SD card: sudo dd if=u-boot.img of=/dev/mmcblk0 bs=1k seek=69; sync - Jumper settings: SW601: 0 0 1 0 Sw602: 1 0 where 0 means bottom position and 1 means top position (from the switch label numbers reference). - Connect the USB cable between the EVK and the PC for the console. (The USB console connector is the one close the push buttons) - Insert the micro SD card in the board, power it up and U-Boot messages should come up.