mirror of https://gitee.com/openkylin/linux.git
0b9cf3aa6b
mdacon incorrectly detects MDA hardware on systems without such graphics card. One may load this module by chance, for example when doing some systematical module-testing, and if there is no Monochrome Display Adapter attached , module init renders vc1-16 completely unusable. I and others have run into this more than once. see [Bug 224522 - modprobe mdacon freezes machine -> https://bugzilla.novell.com/show_bug.cgi?id=224522 ] for example Apparently proper MDA detection seems to be broken for a long time - seems to be related to those #ifdef TEST_MDA_B statements added by Edward Betts. this commit back in 2002 made things even worse : http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commit;h=c72757b49c88914433244757fb4967fc63546685 It changed default vc allocation from 13-16 to 1-16 for no apparent reason (!?) , and with that (and without X), mdacon grabs the vc you`re currently sitting on and locks you out. this is from Kconfig : >config MDA_CONSOLE > depends on !M68K && !PARISC && ISA > tristate "MDA text console (dual-headed) (EXPERIMENTAL)" > ---help--- > Say Y here if you have an old MDA or monochrome Hercules graphics > adapter in your system acting as a second head ( = video card). You > will then be able to use two monitors with your Linux system. Do not > say Y here if your MDA card is the primary card in your system; the > normal VGA driver will handle it. As we can see mdacon is just meant as an additional driver for dual-head setup, and since kernel 2.4.36 still defaults to vc13-16 , setting the default back to that value again shouldn`t do any harm. Hereby i'm reverting that change, setting default back to to vc13-16 again. Besides the fact that mdacon may be rarely or never be used these days and could perhaps put to trash anyway (pre-dinosaur hardware!), indeed this is not a real solution, but at least it removes the unfortunate side-effect of messing up the vc you`re working on. Signed-off-by: Roland Kletzing <devzero@web.de> Cc: James Simmons <jsimmons@infradead.org> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: Tim Schmielau <tim@physik3.uni-rostock.de> Cc: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| accessibility | ||
| acpi | ||
| amba | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| block | ||
| bluetooth | ||
| cdrom | ||
| char | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| dca | ||
| dio | ||
| dma | ||
| edac | ||
| eisa | ||
| firewire | ||
| firmware | ||
| gpio | ||
| gpu | ||
| hid | ||
| hwmon | ||
| i2c | ||
| ide | ||
| ieee1394 | ||
| infiniband | ||
| input | ||
| isdn | ||
| leds | ||
| lguest | ||
| macintosh | ||
| mca | ||
| md | ||
| media | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nubus | ||
| of | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| pnp | ||
| power | ||
| ps3 | ||
| rapidio | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| serial | ||
| sh | ||
| sn | ||
| spi | ||
| ssb | ||
| tc | ||
| telephony | ||
| thermal | ||
| uio | ||
| usb | ||
| video | ||
| virtio | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||