[ltp] Savage Kernel Driver Problems (T21)

[Alex Deucher]

On Sun, 20 Mar 2005 22:09:12 -0700, Kevin Locke <kwl7@cornell.edu> wrote:
> Hi all,
> 
> After recently installing Linux on a T21, I have been having a few
> problems with the savage driver in the 2.6.10 kernel and I wanted to
> know if anyone else on the list has encountered these problems or if
> there are any known workarounds.
> 
> For the following discussion, "with savage" means the kernel was
> compiled with:
> CONFIG_FB_VESA=n
> CONFIG_FB_SAVAGE=y
> CONFIG_FB_SAVAGE_I2C=y
> CONFIG_FB_SAVAGE_ACCEL=n     (completely garbles the screen)
> and "with vesafb" means:
> CONFIG_FB_VESA=y
> CONFIG_FB_SAVAGE=n
> and both have
> CONFIG_VIDEO_SELECT=y
> CONFIG_FRAMEBUFFER_CONSOLE=y
> 
> First, with the savage driver, when I use a video mode with a resolution
> of 1024x768 (e.g. vga=0x305) there is a large black border around the
> screen text (it looks the same as using an 800x600 resolution and
> turning off video-expansion in the BIOS).  The problem only appears in
> the console, inside X the black border disappears.  With vesafb, video
> modes with 1024x768 look great, no black border.
> 
> Second, with the savage driver, I am unable to resume the computer from
> standby.  After "echo standby > /sys/power/state" from single-user mode
> the computer goes to sleep, but after pressing the Fn key to wake the
> machine "state: 1" is displayed in the upper left corner of the screen
> and the system becomes completely unresponsive, requiring a reboot.
> With vesafb, the system enters and exits standby without problems (even
> from within X).
> 
> Third, with both savage and vesafb, when the computer enters standby the
> screen is filled with a wash of colors that fades out from the center.
> There are also colorful vertical lines that appear in the center of the
> screen (this is all very hard to describe, but rather beautiful to
> watch ;)  I am not overly concerned about this, since using vbetool to
> turn off the monitor first should solve the problem, but I thought it
> was worth a mention if only for the oddity of the effects (possibly
> generated by random discharges?).
> 
> I do not know if there is any reason not to just switch to vesafb, but
> if these problems are happening on other machines it would probably be
> worth reporting to the kernel BTS.
> 
> Thanks in advance,
> Kevin
> 

Several people have reported problems with savagefb and the X savage
driver.  They don't play together nicely (probably some regs that are
not properly saved/restored).  Also, I'm not sure if savagefb has
proper support for panels or not.  My understanding is that the
savagefb module is pretty basic.

Alex