[Nouveau] NvClkMode and NvMemExec Options

[Joseph D. Wagner]

On 2016-12-16 12:52, Ilia Mirkin wrote:

> On Fri, Dec 16, 2016 at 12:10 PM, Joseph D. Wagner
> <joe at josephdwagner.info> wrote:
> 
>> When using the nouveau driver, my screen freezes (and stays frozen) 
>> when it
>> starts to more than a minimum amount of work.  To fix this, I've been 
>> using
>> the nvidia driver with the Preferred Mode set to Prefer Maximum 
>> Performance.
>> 
>> It looks like equivalent settings in nouveau are NvClkMode and 
>> NvMemExec.
>> However, I didn't see any documentation specifying the valid options 
>> for
>> these settings?
>> 
>> What are the valid options for NvClkMode?
> 
> This takes the decimal (!) value of the pstate you want to clock to on
> boot. The valid pstates are defined by your VBIOS, and are visible in
> /sys/kernel/debug/dri/0/pstate (in hex).

These are my options.  I've tried both 14 (0e) and 15 (0f).  Both appear 
to work.  Is there a difference?
07: core 405 MHz memory 648 MHz
0a: core 405-967 MHz memory 1620 MHz
0e: core 405-1241 MHz memory 6008 MHz
0f: core 405-1241 MHz memory 6008 MHz AC DC *
AC: core 405 MHz memory 6007 MHz

0f is currently selected in the above.

> Based on the little information you provided, I doubt your hangs have
> much to do with the performance level. (Unless you meant to say "When
> using the nvidia driver ... ".)

If I run it without NvClkMode at boot time, it will freeze on me after 
moderate use while using the nouveau driver.

If I run it with NvClkMode=14 or NvClkMode=15, it appears to work fine 
(from the small amount of testing I've done).

Joseph D. Wagner