Re: Linux script to enable ASPM / Documentation for ASPM

From: Luis R. Rodriguez
Date: Thu Jan 13 2011 - 22:16:01 EST


On Mon, Jun 21, 2010 at 4:02 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxx> wrote:
> On Mon, Jun 21, 2010 at 3:58 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxx> wrote:
>> ASPM was a dark magic when I first started looking at it. Some of it
>> is still dark but what I was able to understand with the help of
>> colleagues at work I've managed to stash here for now:
>>
>> http://wireless.kernel.org/en/users/Documentation/ASPM
>>
>> Then enabling ASPM was also quite a challenge and I always had to go
>> back and revisit the procedures, so to help with that instead I wrote
>> a script to do this for you correctly:
>>
>> http://kernel.org/pub/linux/kernel/people/mcgrof/aspm/enable-aspm
>>
>> Its sha1sum is: f5804fdab512065f219e55addf78c6654f1fc045
>>
>> If any of that looks confusing refer to the documentation above.
>>
>> There's a TODO there, so I'll get to the different items when I can
>> but if you like feel free to send me patches as well:
>>
>> ÂTODO: patches are welcomed to me until we submit to to
>> Â Â Â PCI Utilities upstream.
>>
>> ÂThis can be improved by in this order:
>>
>> Â Â Â Â* Accept arguments for endpoint and root complex address, and
>> Â Â Â Â Âdesired ASPM settings
>> Â Â Â Â* Look for your ASPM capabilities by quering your
>> Â Â Â Â ÂLnkCap register first. Use these values to let you
>> Â Â Â Â Âselect whether you want to enable only L1 or L1 & L0s
>> Â Â Â Â* Searching for your root complex for you
>> Â Â Â Â* Search for your PCI device by using the driver
>> Â Â Â Â* Disable your driver and ask to reboot ?
>> Â Â Â Â* Rewrite in C
>> Â Â Â Â* Write ncurses interface [ wishlist ]
>> Â Â Â Â* Write GTK/QT interface [ wishlist ]
>> Â Â Â Â* Submit upstream as aspm.c to the PCI Utilities, which are
>> Â Â Â Â Âmaintained by Martin Mares <mj@xxxxxx>
>
> Come to think of it, would this be welcomed upstream in the PCI utils
> as is for now?

New version that'll work with new setpci.

http://kernel.org/pub/linux/kernel/people/mcgrof/aspm/enable-aspm
sha1sum:
f2e6e9a36ff7fe3b875229ee237f605d0695b18a

with this diff:

--- enable-aspm.old 2011-01-14 03:13:33.248428802 +0000
+++ enable-aspm 2011-01-14 03:12:51.711354522 +0000
@@ -161,11 +161,11 @@
exit
fi

- SEARCH=$(setpci -s $1 34)
+ SEARCH=$(setpci -s $1 34.b)
# We know on the first search $SEARCH will not be
# 10 but this simplifies the implementation.
while [[ $SEARCH != 10 && $SEARCH_COUNT -le $MAX_SEARCH ]]; do
- END_SEARCH=$(setpci -s $1 $SEARCH)
+ END_SEARCH=$(setpci -s $1 ${SEARCH}.b)

# Convert hex digits to uppercase for bc
SEARCH_UPPER=$(printf "%X" 0x${SEARCH})
@@ -176,7 +176,7 @@
fi

SEARCH=$(echo "obase=16; ibase=16; $SEARCH + 1" | bc)
- SEARCH=$(setpci -s $1 $SEARCH)
+ SEARCH=$(setpci -s $1 ${SEARCH}.b)

let SEARCH_COUNT=$SEARCH_COUNT+1
done
@@ -200,7 +200,7 @@
return 1
fi

- ASPM_BYTE_HEX=$(setpci -s $1 $ASPM_BYTE_ADDRESS)
+ ASPM_BYTE_HEX=$(setpci -s $1 ${ASPM_BYTE_ADDRESS}.b)
ASPM_BYTE_HEX=$(printf "%X" 0x${ASPM_BYTE_HEX})
# setpci doesn't support a mask on the query yet, only on the set,
# so to verify a setting on a mask we have no other optoin but
@@ -228,11 +228,11 @@
fi

# This only writes the last 3 bits
- setpci -s $1 ${ASPM_BYTE_ADDRESS}=${ASPM_SETTING}:3
+ setpci -s $1 ${ASPM_BYTE_ADDRESS}.b=${ASPM_SETTING}:3

sleep 3

- ACTUAL_ASPM_BYTE_HEX=$(setpci -s $1 ${ASPM_BYTE_ADDRESS})
+ ACTUAL_ASPM_BYTE_HEX=$(setpci -s $1 ${ASPM_BYTE_ADDRESS}.b)
ACTUAL_ASPM_BYTE_HEX=$(printf "%X" 0x${ACTUAL_ASPM_BYTE_HEX})

# Do not retry this if it failed, if it failed to set.
--
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