Two bugs in fbcon?
From: Ondrej Zajicek <hidden>
Date: 2006-05-15 21:03:35
Hello I found that in kernel 2.6.16.16 is some very strange behavior in fbcon. I added some printks to some functions in fbcon and i found this: I am on vt0, i have active vt0-vt3. When i modprobe fbcon (having fbdev driver inserted before), functions fbcon.c/fbcon_init() and fbcon.c/updatescrollmode() are called for each active vt. Order is: fbcon_init(vt0) updatescrollmode(vt0) updatescrollmode(vt1) fbcon_init(vt1) updatescrollmode(vt2) fbcon_init(vt2) updatescrollmode(vt3) fbcon_init(vt3) for vt1-vt3 updatescrollmode is called before fbcon_init which caused that associated struct display::vrows value is computed (in updatescrollmode() - fbcon.c:1970) from old vc->vc_rows (which is updated in fbcon_init()). Now second strangeness - I am still on vt0 (immediately after modprobe fbcon), but during calls to bitblit.c/bit_cursor display structure associated with vt3 is used (in bitblit.c:244 - ops->p). Combined with previous strangeness (bad vrows values in vt1-vt3) i get cursor visible on bad row. When i switch to another vt or switch resolution, then this is corrected (next calls to bitblit.c/bit_cursor are using correct display structure.). I don't understand fbcon enough to correct this problem (and be sure not to make some other :-)). -- Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago@mail.cz, jabber: santiago@njs.netlab.cz) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."
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