Re: DVD choppy

Dotan Cohen wrote:

On 30/01/07, Philip Walden <pwaldenlinux@xxxxxxxxxxx> wrote:

Philip Walden wrote:
> Dotan Cohen wrote:
>> On a recent Dell laptop, what would cause DVD playback to be very
>> choppy?
> Besides the ATA DMA stuff, you may also want to check whether your
> MTRR is being set properly by the xorg X server.
>
> Mine looks like this:
>
> cat /proc/mtrr
> reg00: base=0x00100000 (   1MB), size= 256MB: write-back, count=1
> reg01: base=0xfc000000 (4032MB), size=  32MB: write-combining, count=1
>
> You should have at least one "write-combining" entry which means the
> graphics card is set properly. Otherwise, performance can drop
> dramatically.
Here is a howto:

http://www.faqs.org/docs/Linux-HOWTO/DVD-HOWTO.html#ss6.1

Thanks. I've nothing in /proc/mtrr:

[root@localhost ~]# ls /proc/mtrr
/proc/mtrr

Try:
 cat /proc/mtrr
reg00: base=0x00100000 (   1MB), size= 256MB: write-back, count=1
reg01: base=0xfc000000 (4032MB), size=  32MB: write-combining, count=1

However, I'm having a hard time starting X, as it's already running!
I've combed the logs in /var/logs but I don't have those lines. When I
kill X with CTRL-ALT-ESC it starts right back up automatically, not
letting me redirect it's output to a file.

I found mine using lspci

# /sbin/lspci -v
 :

       Subsystem: ASUSTeK Computer Inc. AGP-V3800 SDRAM
       Flags: bus master, 66MHz, medium devsel, latency 40, IRQ 11
       Memory at f5000000 (32-bit, non-prefetchable) [size=16M]

       Capabilities: [60] Power Management version 1
       Capabilities: [44] AGP version 2.0

I then added this to /etc/rc.local:

# set mtrr at least until Xorg 7.1 is added to the distribution
echo "base=0xfc000000 size=0x2000000 type=write-combining" >| /proc/mtrr

Just for kicks, here's the output of "lspci -v" as suggested by the same page:

  :

01:00.0 VGA compatible controller: ATI Technologies Inc Radeon
Mobility X1400 (prog-if 00 [VGA])
       Subsystem: Dell Unknown device 2003
       Flags: bus master, fast devsel, latency 0, IRQ 4
       Memory at d0000000 (32-bit, prefetchable) [size=256M]

        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

       I/O ports at ee00 [size=256]
       Memory at efdf0000 (32-bit, non-prefetchable) [size=64K]
       [virtual] Expansion ROM at efd00000 [disabled] [size=128K]
       Capabilities: [50] Power Management version 2
       Capabilities: [58] Express Legacy Endpoint IRQ 0
       Capabilities: [80] Message Signalled Interrupts: 64bit+
Queue=0/0 Enable-

I would guess your's would look like:

echo "base=0xd0000000 size=0x10000000 type=write-combining" >| /proc/mtrr