Description of problem: When install RHEL4(any update level) on a ATI ES1000 system,image shifts to right and down. The shift can obscure some of the options at the bottom of the screen. This problem has been seen when using certain flat panel monitors and with remote-KVM systems which use analog video input. The problem is also present with DVI video but is more pronounced from analog sources. Version-Release number of selected component (if applicable): RHEL4 installation kernel How reproducible: always Steps to Reproduce: 1.boot from the RHEL4 Linux install CD (any update level) 2.Press enter at the initial screen (to install in graphics mode). 3.After an initial scrolling of text the screen will blank and more text will appear. This will be shifted noticeably to the right. 4.The first blue“graphical” screen, titled “Welcome to Red Hat Enterprise Linux” will appear shifted right by one or more characters and may also be shifted downward one line. Additional info: Additional testing shows that this problem not only appears on ES1000, but also other manufacures cards
Created attachment 145769 [details] shifted image during RHEL4 installation
RHEL4 install process chooses Vga16fb frame buffer driver to drive the console. Regardless of the mode set by video BOIS during linux setup period, the driver will modify video timing according to its hardcoded video parameters defined in structure fb_var_screeninfo. These parameters define the screen margins as well as the video resolution and result in the shifted screen. here is the detailed timing define by the vga16fb: struct fb_var_screeninfo vga16fb_defined __initdata = { .xres = 640, .yres = 480, .xres_virtual = 640, .yres_virtual = 480, .bits_per_pixel = 4, .activate = FB_ACTIVATE_TEST, .height = -1, .width = -1, .pixclock = 39721, .left_margin = 48, .right_margin = 16, .upper_margin = 39, .lower_margin = 8, .hsync_len = 96, .vsync_len = 2, .vmode = FB_VMODE_NONINTERLACED, }; these hard coded parameter result in timing as follows: 640x480 HTimings:640 656 752 800 VTimings:480 488 490 529
That's pretty awful, but it's not an X problem. Reassigning to the kernel.
Does this problem happen on rhel5 as well? Or do we use vesafb there instead of vga16fb? The code in comment #2 looks exactly the same even in the latest upstream kernel. Not sure if its easier to fix vga16fb or just switch to vesafb instead...
Our customer hasn't found the same problem on rhle5. I found rhel5 doesn't use vga16fb as the console driver, correct me if I am wrong.
Okay, a bit of further investigation says that rhel5 actually uses *no* fb driver at all, just pure text mode. However, running that way generally isn't an option on rhel4, due to some bits that still depend on the fb (primarily, CJK characters). However, if CJK characters aren't needed, one can boot the installer with 'linux nofb' and the offset problem *should* be gone. If that does the trick, I think a release note about it might me more apropos than fixing ancient code that (almost?) nobody uses in more modern kernels.
Please let me know if 'linux nofb' does the trick, and if so, if this is an acceptable workaround.
we accept this workaround. Thanks for your attention.
Okay, I'll flag this bug to get a release note added for 4.7. Thanks much!
This request was evaluated by Red Hat Product Management for inclusion, but this component is not scheduled to be updated in the current Red Hat Enterprise Linux release. If you would like this request to be reviewed for the next minor release, ask your support representative to set the next rhel-x.y flag to "?".
I hate the pm bot sometimes... Don't mind comment #10, we'll get the relnote in...
tracking this bug for RHEL4.7 release notes.
adding to RHEL4.7 release notes under "Installation-Related Notes": <quote> When installing Red Hat Enterprise Linux 4 in Graphical Mode on systems that use flat-panel monitors and some ATI cards, the screen area may appear shifted. When this occurs, some areas of the screen will be obscured. If this occurs, perform the installation with the parameter linux nofb. </quote> Jarod, please advise if any further revisions are required. thanks!
Its actually the text portions of the installer where we get the offset, not the graphical -- see attachment. :)
whoops, missed that one. thanks for the catch, Jarod; source now reads: <snip> When installing Red Hat Enterprise Linux 4 in Text Mode... </snip>
Hi, the RHEL4.7 release notes deadline is on June 17, 2008 (Tuesday). they will undergo a final proofread before being dropped to translation, at which point no further additions or revisions will be entertained. a mockup of the RHEL4.7 release notes can be viewed here: http://intranet.corp.redhat.com/ic/intranet/RHEL4u7relnotesmockup.html please use the aforementioned link to verify if your bugzilla is already in the release notes (if it needs to be). each item in the release notes contains a link to its original bug; as such, you can search through the release notes by bug number. Cheers, Don