Bug 718 - Switching to TTYs from X session gives blank screen
Summary: Switching to TTYs from X session gives blank screen
Status: NEW
Alias: None
Product: AMD Catalyst™Proprietary Display Driver
Classification: Unclassified
Component: Kernel Module (show other bugs)
Version: 13.1
Hardware: Radeon HD 5000 Series Linux
: low normal
Assignee: nobody
: 740 (view as bug list)
Depends on:
Reported: 2013-02-13 09:43 CST by Torin
Modified: 2013-08-08 03:52 CDT (History)
4 users (show)

Report file created by atigetsysteminfo.sh (compressed with XZ) (32.81 KB, application/x-xz)
2013-02-13 09:43 CST, Torin
screenshot of tty on vga=794 (190.64 KB, image/jpeg)
2013-02-13 13:07 CST, Vi0L0
Report generated by atigetsysteminfo.sh (in tar.gz) (39.14 KB, application/x-gzip)
2013-02-13 13:20 CST, Vi0L0

Note You need to log in before you can comment on or make changes to this bug.
Description Torin 2013-02-13 09:43:38 CST
Created attachment 691 [details]
Report file created by atigetsysteminfo.sh (compressed with XZ)


Arch Linux x86_64
Linux kernel 3.7.7
Xorg server 1.13.2
Catalyst 13.2 beta 3


Radeon HD 5670


As soon as the X server starts (this is at boot for me) and my login manager is on the screen, pressing Ctrl + Alt + F1-F6 yields a blank screen. At the blank screen, one may safely return to X with Ctrl + Alt + F7. The effect is that the TTYs cannot be accessed. 

Steps to reproduce:
1. Start X server.
2. Press Ctrl + Alt + (F1 | F2 | F3 | F4 | F5 | F6).

Actual result: Blank screen.

Expected result: Text (a getty login prompt or similar).
Comment 1 Vi0L0 2013-02-13 13:07:57 CST
Created attachment 692 [details]
screenshot of tty on vga=794
Comment 2 Vi0L0 2013-02-13 13:17:33 CST
I can confirm this bug.

Tested on:
- Arch Linux x86_64
- vanilla kernels 3.7.7 and 3.8 rc7
- xorg server 1.13.2
- kde 4.10 and gnome 3.6.2
- radeon hd 7850

when there's no vga= kernel' boot switch and no framebuffer resoulution specified - after switching to tty screen becomes blank

i used to use vga=794 kernel switch and with it i can see screen vertically "splitted" into two cloned screens, readable until line isn't too wide, just like the one i attached

after switching vga= to highest resolution my framebuffer can handle tty becomes clean, pure and just fine.

still it is a bug, tty should always work
Comment 3 Vi0L0 2013-02-13 13:20:08 CST
Created attachment 693 [details]
Report generated by atigetsysteminfo.sh (in tar.gz)
Comment 4 sorath 2013-03-21 03:34:59 CDT
It seems that I described the same bug: http://ati.cchtml.com/show_bug.cgi?id=740

I also got the splited TTY console after X-Server starting.

As I mention there the issue takes place for me with  combination of "sys-kernel/gentoo-sources-3.7" and "x11-drivers/ati-drivers-13.2_beta* (and 13.3_beta*)". 
While with the same "x11-drivers/ati-drivers-13.2_beta*" driver there is no problem on "sys-kernel/gentoo-sources-3.6.11".

Vi0L0, could you say what highest vga resolution you used at which the problem doesn't occurs? My monitor's native resolution is 1680x1050 that isn't compatible with standard VGA regime. I use currently vga=794 (1280x1024x16) for TTY.
Comment 5 sorath 2013-03-21 03:38:49 CDT
*** Bug 740 has been marked as a duplicate of this bug. ***
Comment 6 sorath 2013-03-21 05:14:36 CDT
Maybe this issue is related framebuffer driver.
I'll try to set "vga=normal" (instead of current) parameter for TTY console in my grub2.cfg to disable framebuffer or check what fb-drivers is used.
Comment 7 Vi0L0 2013-03-21 12:02:56 CDT
yes, this could be framebuffer related, but ie. catalyst 13.1 works fine with newer kernels, so i'm blaming latest catalyst' changes.

As for your question:
hwinfo --framebuffer
gave me the list of supported resolutions, i picked up the one from the very bottom (my monitor's native is fullhd), and copy-pasted it into kernel line of my syslinux bootloader, so it looked like vga=0x03d4, and bam - hi-res tty working nicelly when switching from X.
Comment 8 sorath 2013-03-21 14:10:52 CDT

It seems I use "vesafb" driver for TTY console (it compiled into kernel as radeon fb driver):
#hwinfo --framebuffer
02: None 00.0: 11001 VESA Framebuffer

Well, if I set kernel parameter in grub2 "vga=normal" (that must disable framebuffer, afaik) then TTY consoles represents as black screen after starting of X-Server. And after return  back to TTY-7 (with X-Server/KDE) Desktop's redrawing is slow at the first moment after switching.

If I set "vga=0x031a" (1280x1024, 16 bits) - the TTY consoles screen is splitted/corrupted.

If I set "vga=0x0345" (1400x1050, 16 bits) - then TTY consoles looks fine after starting of X-Server

There my configs for 3.6.11 and 3.7.10 gentoo-sources-kernels 
(attached from bug 740)
Comment 9 sorath 2013-03-21 16:49:54 CDT

Desktop's redrawing sometimes slowly at the first moment after switching back from TTY(1-6) even then the TTY console is displayed correctly without corruption.
Comment 10 sorath 2013-05-05 11:50:16 CDT
Issue still represents with ati-drivers-13.4
Comment 11 Anton Zhdanov 2013-08-08 03:52:34 CDT
Removing vga= key from the Grub config made things a bit better - now I can switch between TTYs but now I can't go back to X - the screen becomes black and the only way to fix it is

$ sudo service kdm restart