Bug#647858: loading kernel module viafb blacks out Sylvania G netbook

[Jonathan Nieder <jrnieder@gmail.com>]

Tzafrir Cohen wrote:

> Attached. There fas an fsck which has delayed the boot. sdb is a card
> readers, and is empty.

Thanks.

[...]
> I'm not exactly sure what would "upstream" be.

That's exactly the right line of reasoning.

It sounds like preventing viafb from loading does not avoid trouble,
so the trick would be to find some driver or facility to disable that
_does_ avoid trouble.  Then we can punt to the person responsible for
that subsystem. :)

[...]
> ACPI: Actual Package length (8) is larger than NumElements field (5), truncated
[3x]

Doesn't look frightening, but please attach "acpidump" output for
reference anyway.

[...]
> PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug

I doubt this is the cause; still, it's worth a try, too.

[...]
> pci 0000:02:01.0: disabling ASPM on pre-1.1 PCIe device.  You can enable it with 'pcie_aspm=force'
[...]
> ACPI _OSC control for PCIe not granted, disabling ASPM

There's a recent patch in the PCI tree (but not in mainline yet) that
might change this behavior and which I am rather fond of (7f92c4f7d92a,
"PCI: Rework ASPM disable code", 2011-11-10).  Attaching it in case
you want to try it.

[...]
> usb 1-4: New USB device found, idVendor=0bda, idProduct=8187
> usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 1-4: Product: RTL8187_Wireless

I assume the same symptoms are present even when the wireless card is
not attached.  Worth checking if you haven't tried already.

[...]
> viafb: Unknown parameter `bogusarg'

Cute.  That reminds me: is X running when the hangs happen?

[...]
> sd 2:0:0:0: [sdb] Test WP failed, assume Write Enabled
> sd 2:0:0:0: [sdb] Asking for cache data failed
> sd 2:0:0:0: [sdb] Assuming drive cache: write through
(many times)

Can you blacklist the ums-realtek driver?  Output from booting with
the CONFIG_USB_STORAGE_DEBUG compile-time configuration option enabled
("make nconfig" → Device Drivers → USB support → USB Mass Storage
support → USB Mass Storage verbose debug) would also be interesting.

[...]
> I was not able to get anyt sort of error trace of message from the hung
> system, even when it was on the console.

I assume this means the magic sysrq key wasn't working in that state.
Alas.

Thanks for the quick feedback.

Hope that helps,
Jonathan