AM335x: Cannot set PRM_RSTTIME register under Linux

Andrei Pushkin

Hello. I need to set big value to PRM_RSTTIME register, to reset Ethernet PHY while reboot.

I apply patch http://patchwork.ozlabs.org/patch/197551/ and see that in u-boot warm reset time is increased. (I see it using oscilloscope and do command "reset" ini u-boot). Also I see that is setted by u-boot console:

Maui loader> md 0x44E00F04
44e00f04: 000010ff 00000001 78000017 00000003 ...........x....

(ff - is my delay time)

But in Linux big warm reset time is not apply. Is only minimal, like default. I can read value from this register, it is my:

# devmem 0x44E00F04
0x000010FF
#

How I can fix this problem? Why Linux 'ignore' PRM_RSTTIME register ?

May be its connected with Linux flash power firmware?

over 11 years ago

0 Schuyler Patton over 11 years ago

TI__Mastermind 40080 points

From your printout it looks like the devmem2 0x44E00F04 is displaying the same results as the mem display command in u-boot. This is the value you wanted?

The devmem2 output I see on my board for 0x44E00F04 is 0x00001006 which looks to be the default in the TRM.

0 Andrei Pushkin over 11 years ago in reply to Schuyler Patton

Intellectual 705 points

>>From your printout it looks like the devmem2 0x44E00F04 is displaying the same results as the mem display command in u-boot. This is the value you wanted?

Yes. Values is tha same. But in u-boot its work (reset command in u-boot show me needed warm reset delay), in Linux its not work (reboot command in linux show me very small wark reset delay, not like u-boot). I check Linux code and see that Linux not change this register or registers from it group.

>>The devmem2 output I see on my board for 0x44E00F04 is 0x00001006 which looks to be the default in the TRM.

6 - its default value, its to small for me. ff - its value that write my u-boot patch.