HP Compaq 6715s

Bad kernels

 * Don't use:
 * the kernels from 3.4.x up to 3.7.x. (Fixed in 3.8) For them, you can apply a patch available here. See CPU stuck at minimum frequency - HP Compaq 6715b for the details.
 * the kernel 3.4.x. It's fixed in >= 3.5 by this patch.
 * the kernel 2.6.38.2 if you use s2disk. It's fixed in 2.6.38.3.
 * the kernels 2.6.38 and 2.6.38.1. (&ge; 2.6.38.2 are ok.) The fan runs at full speed!
 * the kernel 2.6.37 if you use s2ram. See below.

Introduction
The HP Compaq 6715s is a notebook which comes with 64-bit AMD or Intel CPU, and 15.4 widescreen monitor. Typically it consists of Turion X2, 1 Gb RAM, 160 Gb sata disk and Broadcom wireless 802.11b/g.

Compaq 6715b is an elder brother.

Description of the hardware
here's the output of lspci:


 * 1) lspci

Graphics Drivers
You should follow the radeon guide. Modern versions of fglrx no longer support this card.

Bad kms versions
KMS is supported, but one of some versions of kernels doesn't work.
 * It works with 2.6.32. Some later version introduced a bug.
 * The fix is done in 3.0.9, 3.1.1, and 3.2. See bug 37679 in freedesktop.org bugzilla.

Wireless
See the Broadcom 43xx article.

s2ram

 * gentoo-sources-2.6.37: Don't use it. Lolo has tried only once, but after s2ram, the fan stopped working. And lm_sensors don't alarm.

Suspend to ram (s2ram) works fine in X, but console use needs care, regardless of VGA or framebuffer.

There're many variants of 6715s, and necessary flags vary among them, and among kernel versions. For console use, try:
 * (This works for Lolo]].)

Also in X, it is recommendable to pass. This prevents console corruption.

s2disk
It works fine with "platform" method, at least on kernel 2.6.38.

Misc
There is also reports about non-functioning PXE / UNDI netboot and hardships with USB booting in general. Also BIOS upgrade is prevented in some models. Hp customer advisory c01457784

s2disk
If you use "shutdown" method for s2disk, you may run into trouble; it works, but often, not always, fan does not work after resume'', so it's very dangerous. On some versions of kernel, s2ram fails after a resume from s2disk.

Freeze Issue
In the past, some, not all, of 6715b and 6715s used to freeze randomly.

You can prevent it by an appropriate kernel boot option. Listing from better ones:
 * (none): with kernel &gt;=2.6.31.
 * edd=skipmbr (Or edd=off. Cpu can go C3 state. Doesn't work for kernel &lt;=2.6.28)
 * processor.max_cstate=2
 * nohz=off
 * acpi=off (no powersave, fan)

Don't forget to update bios to Nov 2008 version!

General description
Some, not all, of 6715b and 6715s freeze randomly. The screen turns black, and anything, including key inputs, are not accepted at all, so the real lock up. Hang is often random, and you may not be able to trigger it deliberately.

There're many reports of this problem under Microsoft Windows, regardless of XP or Vista. Although few under Linux, the problem is there.

The cause for Windows is speculated to be the fault of the hardware. But Linux hangs may be of different nature. Linux kernel hangs are not rare in recent machines.