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vesa: fix panic on suspend

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Fix the following panic seen when migrating a FreeBSD guest on Xen:

panic: mtx_lock() of destroyed mutex @ /usr/src/sys/dev/fb/vesa.c:541
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe001d2fa4f0
vpanic() at vpanic+0x182/frame 0xfffffe001d2fa570
kassert_panic() at kassert_panic+0x126/frame 0xfffffe001d2fa5e0
__mtx_lock_flags() at __mtx_lock_flags+0x15b/frame 0xfffffe001d2fa630
vesa_bios_save_restore() at vesa_bios_save_restore+0x78/frame 0xfffffe001d2fa680
vga_suspend() at vga_suspend+0xa3/frame 0xfffffe001d2fa6b0
isavga_suspend() at isavga_suspend+0x1d/frame 0xfffffe001d2fa6d0
bus_generic_suspend_child() at bus_generic_suspend_child+0x44/frame
[...]

This is caused because vga_sub_configure (which is called if the VGA adapter
is attached after VESA tried to initialize), points to vesa_configure, which
doesn't initialize the VESA mutex. In order to fix it, make sure
vga_sub_configure points to vesa_load, so that all the needed vesa
components are properly initialized.

Sponsored by:		Citrix Systems R&D
MFC after:		3 days
PR:			209203
Reviewed by:		dumbbell
Differential revision:	https://reviews.freebsd.org/D7196
This commit is contained in:
Roger Pau Monné 2016-07-20 09:29:39 +00:00
parent aed721ec51
commit c397b61ea5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=303076
1 changed files with 14 additions and 2 deletions
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16
sys/dev/fb/vesa.c
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@ -134,6 +134,7 @@ static vi_fill_rect_t vesa_fill_rect;
static vi_bitblt_t vesa_bitblt;
static vi_diag_t vesa_diag;
static int vesa_bios_info(int level);
static int vesa_late_load(int flags);
static video_switch_t vesavidsw = {
vesa_probe,
@ -1141,7 +1142,7 @@ vesa_configure(int flags)
* initialization for now and try again later.
*/
if (adp == NULL) {
vga_sub_configure = vesa_configure;
vga_sub_configure = vesa_late_load;
return (ENODEV);
}
@ -1908,6 +1909,17 @@ vesa_bios_info(int level)
static int
vesa_load(void)
{
return (vesa_late_load(0));
}
/*
* To be called from the vga_sub_configure hook in case the VGA adapter is
* not found when VESA is loaded.
*/
static int
vesa_late_load(int flags)
{
int error;
@ -1918,7 +1930,7 @@ vesa_load(void)
/* locate a VGA adapter */
vesa_adp = NULL;
error = vesa_configure(0);
error = vesa_configure(flags);
if (error == 0)
vesa_bios_info(bootverbose);