Red Hat Bugzilla – Bug 72734
RFE: keep old monitor info if no ddc
Last modified: 2007-04-18 12:46:04 EDT
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Description of problem:
If DDC probe fails, then currently pyxf86config assumes bog-standard VESA VGA
for monitor, especially including HorizSync 31.5-37.9 and VertRefresh 50.0-70.0.
So if the user changes the video card, then the existing monitor info must be
retrieved from XF86Config.backup. This would be only annoying, except that
under the default graphical login there is no opportunity to edit XF86Config
after kudzu and before XF86Config is used.
Instead, if DDC probe fails, and if an old XF86Config exists, then by default
pyxf86config should preserve the old monitor info; and if pyxf86config is run
interactively, then there should be a question "Preserve old monitor info
(namely <model>, <freqs>)?" with a default of Yes.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Old video card: Cirrus Logic 5434-8; monitor: Sony Multiscan 15sf (FCC id
AK8CPD15SF1; Nov.1994) with no DDC.
2. Change video card to ATI Rage XL (PCI 0x1002,0x4752).
3. Kudzu detects change, user selects De-configure old card, user selects
Configure new card. DDC Probe returns "None" four times.
Actual Results: VESA VGA monitor info:
HorizSync 31.5 - 37.9
VertRefresh 50.0 - 70.0
ModeLine "1400x1050" 129.0 1400 1464 1656 1960 1050 1051 1054 1100
ModeLine "1400x1050" 151.0 1400 1464 1656 1960 1050 1051 1054 1100
ModeLine "1400x1050" 162.0 1400 1464 1656 1960 1050 1051 1054 1100
ModeLine "1400x1050" 184.0 1400 1464 1656 1960 1050 1051 1054 1100
Expected Results: Keep old monitor info:
notting, I'm not sure what's being asked here. pyxf86config doesn't ever do dcc
probes. And redhat-config-xfree86 should be using the old X config file if it
existed (and --reconfig wasn't specified).
What is kudzu calling here?
kudzu just does the ddc probe; if they customized the monitor before, it won't
find it (and can't; there's no code to parse X config files in kudzu.)
So why was this bug assigned to pyxf86config?
It seems kudzu could easily use pyxf86config to read the old values if it wanted.
It was assigned because of the summary.
I don't think that's the right solution; I think perhaps redhat-config-xfree86
should default to the old values if when it calls kudzu it can't find a monitor.
Having the probe code itself go looking for old data could lead to false positives.
It already does, unless you pass --reconfig.
Or it's a bug.
This is really a redhat-config-xfree86 bug.
I have simplified the monitor selection screen in
system-config-display so I'm not sure if this behavior still happens.
If you see this behavior with Fedora Core 1, please reopen this bug