Hi all,
In my i.MX6 Quad SD (SABRE Board for Smart Devices Based on the i.MX 6 Series Product Summary Page), I cannot set the CPU frequency to 1GHz by using the driver of the linux-3.0.35. WHY?
I a using Ltib, the latest version
I have only frequencies 792MHz and 400MHz available.
My conf:
-Board iMX6Q_SDB (SCH - 27516 rev B3)
-Processor ref: PCIMX6Q6AVT10AB
Thks
Solved! Go to Solution.
Hi, Maurice
I think that maybe because your i.MX6Q chip's fuse is not set to run at max freq = 800M, you can read the fuse value to double check, the fuse map is as below, SPEED_GRANDING field is located in OCOTP offset 0x440, bit [16 - 17], you can read it in uboot with command "imxotp read 4 ". If it is indeed set to 800M, then you may need to blow it to 1G, our uboot also provide the tool to blown the fuse, use command "imxotp blow --force 4 <value>", you can refer to the help of imxotp command in uboot for detail, please be careful about blown fuse, as it is irreversible. After setting done, you may need to power off the board and re-power on, then it should be OK to run at 1GHz.
367 * SPEED_GRADING[1:0] defines the max speed of ARM:
368 * 2b'11: 1200000000Hz;
369 * 2b'10: 1000000000Hz;
370 * 2b'01: 850000000Hz; -- i.MX6Q Only, exclusive with 1GHz.
371 * 2b'00: 800000000Hz;
Hi, Maurice
I think that maybe because your i.MX6Q chip's fuse is not set to run at max freq = 800M, you can read the fuse value to double check, the fuse map is as below, SPEED_GRANDING field is located in OCOTP offset 0x440, bit [16 - 17], you can read it in uboot with command "imxotp read 4 ". If it is indeed set to 800M, then you may need to blow it to 1G, our uboot also provide the tool to blown the fuse, use command "imxotp blow --force 4 <value>", you can refer to the help of imxotp command in uboot for detail, please be careful about blown fuse, as it is irreversible. After setting done, you may need to power off the board and re-power on, then it should be OK to run at 1GHz.
367 * SPEED_GRADING[1:0] defines the max speed of ARM:
368 * 2b'11: 1200000000Hz;
369 * 2b'10: 1000000000Hz;
370 * 2b'01: 850000000Hz; -- i.MX6Q Only, exclusive with 1GHz.
371 * 2b'00: 800000000Hz;
Hi all,
I have some follow up questions on the same issue (I have the i.MX 6 SABRE DualLite version).
Regards,
/joel
Hi,
Thank you. I tried your command and I got:
Reading fuse at index: 0x4
Fuse at (index: 0x4) value: 0x702
So it is meaning that I have 2b'00 (800MHz) at the SPEED_GRADING[1:0] field. Am I right?
I think I will not blow the fuse to 1GHz.