On 30/08/2016 01:37, Fabio Estevam wrote:
From: Fabio Estevam fabio.estevam@nxp.com
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
Applied (all series as fix !) to u-boot-imx, thanks !
Best regards, Stefano Babic