On Tue, 02 Jun 2009 11:13:30 -0400, Joseph Smith joe@settoplinux.org wrote:
Hello, Was anyone aware we are doing the do_ram_command() wrong on the i8xx nothbridges? We are sending the ram commands to all memory and doing our dummy reads
at
the end. I just found an Intel doc that says we are supposed to do all the ram commands to each row of memory.
Quoting from doc:
- Steps for JEDEC initilization for SDRAM devices during boot up:
a. NOP command b. Pre-charge all banks (at least 200 us after NOP) c. 8 CBR refreshes (Auto Refresh) d. MRS command e. Set GMCH-M Mode Select bits back to NORMAL operation mode f. Perform a dummy memory read cycle 2. Repeat this sequence for all memory rows for all SO-DIMMs 3. Test all memory rows after JEDEC initialization sequence is done on
all
memory rows
I will work on a patch for the i830, we should probibly fix this on the other Intle northbridges.
Good news :-) I have the above method working on the i830. I just want to do a little more testing before I submit a patch.