Re: Linux 2.4 Status / TODO page (Updated as of 2.4.0-test10)

James Simmons
2000-11-03T18:10:50Z

> * VGA Console can cause SMP deadlock when doing printk {CRITICAL}
> (Keith Owens)

Still not fixed :-( Here is the patch again. Keith give it a try and tell
me if it solves your problems.

--- vgacon.c.orig Tue Oct 24 18:45:58 2000
+++ vgacon.c Tue Oct 24 19:08:51 2000
@@ -46,11 +46,13 @@
#include <linux/malloc.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
+#include <linux/spinlock.h>
#include <linux/ioport.h>
#include <linux/init.h>

#include <asm/io.h>

+static spinlock_t vga_lock = SPIN_LOCK_UNLOCKED;

#define BLANK 0x0020

@@ -152,8 +154,7 @@
* ddprintk might set the console position from interrupt
* handlers, thus the write has to be IRQ-atomic.
*/
- save_flags(flags);
- cli();
+ spin_lock_irqsave(&vga_lock, flags);

#ifndef SLOW_VGA
v1 = reg + (val & 0xff00);
@@ -166,7 +167,7 @@
outb_p(reg+1, vga_video_port_reg);
outb_p(val & 0xff, vga_video_port_val);
#endif
- restore_flags(flags);
+ spin_unlock_irqrestore(&vga_lock, flags);
}

static const char __init *vgacon_startup(void)
@@ -415,7 +416,7 @@
if ((from == lastfrom) && (to == lastto)) return;
lastfrom = from; lastto = to;

- save_flags(flags); cli();
+ spin_lock_irqsave(&vga_lock, flags);
outb_p(0x0a, vga_video_port_reg); /* Cursor start */
curs = inb_p(vga_video_port_val);
outb_p(0x0b, vga_video_port_reg); /* Cursor end */
@@ -428,7 +429,7 @@
outb_p(curs, vga_video_port_val);
outb_p(0x0b, vga_video_port_reg); /* Cursor end */
outb_p(cure, vga_video_port_val);
- restore_flags(flags);
+ spin_unlock_irqrestore(&vga_lock, flags);
}

static void vgacon_cursor(struct vc_data *c, int mode)
@@ -533,11 +534,11 @@
{
/* save original values of VGA controller registers */
if(!vga_vesa_blanked) {
- cli();
+ spin_lock_irq(&vga_lock);
vga_state.SeqCtrlIndex = inb_p(seq_port_reg);
vga_state.CrtCtrlIndex = inb_p(vga_video_port_reg);
vga_state.CrtMiscIO = inb_p(video_misc_rd);
- sti();
+ spin_unlock_irq(&vga_lock);

outb_p(0x00,vga_video_port_reg); /* HorizontalTotal */
vga_state.HorizontalTotal = inb_p(vga_video_port_val);
@@ -561,7 +562,7 @@

/* assure that video is enabled */
/* "0x20" is VIDEO_ENABLE_bit in register 01 of sequencer */
- cli();
+ spin_lock_irq(&vga_lock);
outb_p(0x01,seq_port_reg);
outb_p(vga_state.ClockingMode | 0x20,seq_port_val);

@@ -598,13 +599,13 @@
/* restore both index registers */
outb_p(vga_state.SeqCtrlIndex,seq_port_reg);
outb_p(vga_state.CrtCtrlIndex,vga_video_port_reg);
- sti();
+ spin_unlock_irq(&vga_lock);
}

static void vga_vesa_unblank(void)
{
/* restore original values of VGA controller registers */
- cli();
+ spin_lock_irq(&vga_lock);
outb_p(vga_state.CrtMiscIO,video_misc_wr);

outb_p(0x00,vga_video_port_reg); /* HorizontalTotal */
@@ -629,7 +630,7 @@
/* restore index/control registers */
outb_p(vga_state.SeqCtrlIndex,seq_port_reg);
outb_p(vga_state.CrtCtrlIndex,vga_video_port_reg);
- sti();
+ spin_unlock_irq(&vga_lock);
}

static void vga_pal_blank(void)
@@ -750,7 +751,7 @@
charmap += 4*cmapsz;
#endif

- cli();
+ spin_lock_irq(&vga_lock);
outb_p( 0x00, seq_port_reg ); /* First, the sequencer */
outb_p( 0x01, seq_port_val ); /* Synchronous reset */
outb_p( 0x02, seq_port_reg );
@@ -766,7 +767,7 @@
outb_p( 0x00, gr_port_val ); /* disable odd-even addressing */
outb_p( 0x06, gr_port_reg );
outb_p( 0x00, gr_port_val ); /* map start at A000:0000 */
- sti();
+ spin_unlock_irq(&vga_lock);

if (arg) {
if (set)
@@ -793,7 +794,7 @@
}
}

- cli();
+ spin_lock_irq(&vga_lock);
outb_p( 0x00, seq_port_reg ); /* First, the sequencer */
outb_p( 0x01, seq_port_val ); /* Synchronous reset */
outb_p( 0x02, seq_port_reg );
@@ -833,8 +834,7 @@
inb_p( video_port_status );
outb_p ( 0x20, attrib_port );
}
- sti();
-
+ spin_unlock_irq(&vga_lock);
return 0;
}

@@ -865,12 +865,12 @@
registers; they are write-only on EGA, but it appears that they
are all don't care bits on EGA, so I guess it doesn't matter. */

- cli();
+ spin_lock_irq(&vga_lock);
outb_p( 0x07, vga_video_port_reg ); /* CRTC overflow register */
ovr = inb_p(vga_video_port_val);
outb_p( 0x09, vga_video_port_reg ); /* Font size register */
fsr = inb_p(vga_video_port_val);
- sti();
+ spin_lock_irq(&vga_lock);

vde = maxscan & 0xff; /* Vertical display end reg */
ovr = (ovr & 0xbd) + /* Overflow register */
@@ -878,14 +878,14 @@
((maxscan & 0x200) >> 3);
fsr = (fsr & 0xe0) + (fontheight-1); /* Font size register */

- cli();
+ spin_lock_irq(&vga_lock);
outb_p( 0x07, vga_video_port_reg ); /* CRTC overflow register */
outb_p( ovr, vga_video_port_val );
outb_p( 0x09, vga_video_port_reg ); /* Font size */
outb_p( fsr, vga_video_port_val );
outb_p( 0x12, vga_video_port_reg ); /* Vertical display limit */
outb_p( vde, vga_video_port_val );
- sti();
+ spin_unlock_irq(&vga_lock);

vc_resize_all(rows, 0); /* Adjust console size */
return 0;