On 09/24/2010 10:07 AM, Randy Dunlap wrote:

On Thu, 23 Sep 2010 18:31:32 +0200 Uwe Bonnes wrote:

[just adding cc's]

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> "Randy" == Randy Dunlap rdunlap@xenotime.net writes: >

Randy> Is CONFIG_DRM_KMS_HELPER enabled in your kernel .config file?  If
Randy> not, we need to find out how to enable it (there is no kconfig
Randy> prompt for it).

Yes, it is enabled

Randy> Can you check if Alt-Sysrq-H (help) lists V for "force-fb(V)"?

Yes, it is listed.

And yes, my last experiments where with ALT-CTL-sysreq, so doomed for non function due to operator error.

However: When running X, X.Org X Server 1.9.0 on Thinkpad R50 RV250, Alt-Sysrq-v switches to an all-black display. By console switching with ALT-CLT-F1 I get back to the booting console and ALT-CLT-F7 brings me back to X. Running on the console and calling Alt-Sysrq-v prints SysRq : Restore framebuffer console

Is there some omission by the distribution or my setup that Alt-Sysrq-v when running X results in an all-black screen?

And when I hit the hibernate problem, the screen stays black even with a console switch after Alt-Sysrq-v

I am not exactly sure what you are looking for but alt-sysrq-v might not tell you a whole lot because an escape back to the text console that was not actively receiving printk's or crash data is going to in general provide you with a black screen.

If you were interested in something a bit more invasive such as a collecting a process listing or examining the dmesg output you might consider jumping into kdb.

echo kbd > /sys/module/kgdboc/parameters/kgdboc

Then you would do the "alt-sysrq v" followed by "alt-sysrq g". From there you could then run dmesg, and your screen would no longer be blank in theory. :-)

We do have some patches for the RV250 for atomic kernel mode setting plus kdb support but they are not merged to the mainline kernels as of yet.

Jason.