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[Federico Tello Gentile <1386973@xxxxxxxxxxxxxxxxxx>]

https://github.com/alterapraxisptyltd/openatom/issues/1

Quote:
[linux] Infinite loop in pci_get_rom_size()

This is one of those issues that you find when putting supposedly stable
code through unusual situations. I did expect any function in linux that
is not part of radeon.ko to not be rock solid. Turns out that's not
really the case.

If we have a PCIR structure with a zero size length, the loop iterating
through those structure does not advance. It simply does "image +=
readw(pds + 16) * 512;", but if that field is zero we're back analyzing
the same structure on the next loop. The way to get out of this loop is
to set bit 7 of the type field. That's what 'last_image' does. If that
bit is not set, with the above, that's an infinite loop.

Luckily, it doesn't crash the kernel, but it hangs any driver that calls
the function under said circumstances. No more modprobe -r or unbinding.
Reboot is needed. No idea why a firmware blob here is treated as trusted
input.

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Packages, which is subscribed to xorg-server in Ubuntu.
https://bugs.launchpad.net/bugs/1386973

Title:
  Ubuntu 14.10 soft lockup with ATI Radeon R7 250 X

Status in xorg-server package in Ubuntu:
  New

Bug description:
  I have a VGA controller Advanced Micro Devices, Inc. [AMD/ATI] Cape Verde XT [Radeon HD 7770/8760 / R7 250X].
  When I boot from the Utopic DVD I get to the language menu and I can select try ubuntu without installing, but after a few sencods I get "BUG: soft lockup - CPU#0 stuck for 22s!'" and the message just repeats every 22 secods forever.

  I tried setting nomodeset using the F6 menu, but I got exactly the
  same result.

  This is Ubuntu 14.10 64 bits which basically seems unable to boot with
  that hardware.

  The experience was the same with 14.04, but I thought 14.10 would be
  better. In 14.04 disabling the video card and booting off the
  integrated graphics let me set nomodeset in /etc/default/grub and I
  was able boot with the R7 250X with the VESA driver. Installed
  Catalyst afterwards.

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