More info on port 80 symptoms on MCP51 machine.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Sadly, I've been busy with other crises in my day job for the last few days. I did modify Rene's test program and ran it on my "problem" machine, with the results below.

The interesting part of this is that port 80 seems to respond to "in" instructions faster than the presumably "unused" ports 0xEC and 0XEF (those were mentioned by someone as alternatives to port 80).

That, and the fact that the port 80 test reliably freezes the machine solid the second time it is run, and the "hwclock" utility reliably hangs the machine if the port 80's are used in the CMOS_READ/CMOS_WRITE loop, seems to strongly indicate that this chipset or motherboard actually uses port 80, rather than there being a bus problem.

Someone might have an in to nVidia to clarify this, since I don't. In any case, the udelay(2) approach seems to be a safe fix for this machine.

Hope input from an "outsider" is helpful in going forward. I put a lot of time and effort into tracking down this problem on this particular machine model, largely because I like the machine.

Running the (slightly modified to test ports 80, ec, ef instead of just port 80) test when the 2 GHz max speed CPU is running at 800 MHz, here's what I get for port 80 and port ec and port ef.

port 80:   cycles: out 1430, in 792
port ef:    cycles: out 1431, in 1378
port ec:   cycles: out 1432, in 1372
----------------------------

System info:  HP Pavilion dv9000z laptop (AMD64x2)

PCI bus controller is nVidia MCP51.
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 72
model name      : AMD Turion(tm) 64 X2 Mobile Technology TL-60
stepping        : 2
cpu MHz         : 800.000
cache size      : 512 KB
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux