Changeset c263c77 in mainline

Timestamp:

2011-05-20T23:12:26Z (14 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

0c33b1d5

Parents:

b6f3e7e

Message:

revert poisonous part of changeset mainline,971
(sadly, this reopens #243)

Location:

kernel

Files:

• genarch/src/drivers/ega/ega.c (modified) (7 diffs)
• genarch/src/fb/fb.c (modified) (5 diffs)
• generic/src/synch/spinlock.c (modified) (1 diff)

kernel/genarch/src/drivers/ega/ega.c

@@ -40 +40 @@
 #include <mm/as.h>
 #include <mm/slab.h>
-#include <synch/mutex.h>
 #include <arch/mm/page.h>
 #include <typedefs.h>
@@ -63 +62 @@
 
 typedef struct {
-        mutex_t mtx;
+        IRQ_SPINLOCK_DECLARE(lock);
         
         uint32_t cursor;
@@ -540 +539 @@
         ega_instance_t *instance = (ega_instance_t *) dev->data;
         
-        mutex_lock(&instance->mtx);
+        irq_spinlock_lock(&instance->lock, true);
         
         switch (ch) {
@@ -563 +562 @@
         ega_move_cursor(instance, silent);
         
-        mutex_unlock(&instance->mtx);
+        irq_spinlock_unlock(&instance->lock, true);
 }
 
@@ -570 +569 @@
         ega_instance_t *instance = (ega_instance_t *) dev->data;
         
-        mutex_lock(&instance->mtx);
+        irq_spinlock_lock(&instance->lock, true);
         
         memcpy(instance->addr, instance->backbuf, EGA_VRAM_SIZE);
@@ -576 +575 @@
         ega_show_cursor(instance, silent);
         
-        mutex_unlock(&instance->mtx);
+        irq_spinlock_unlock(&instance->lock, true);
 }
 
@@ -594 +593 @@
         egadev->data = instance;
         
-        mutex_initialize(&instance->mtx, MUTEX_PASSIVE);
+        irq_spinlock_initialize(&instance->lock, "*ega.instance.lock");
         
         instance->base = base;

kernel/genarch/src/fb/fb.c

@@ -80 +80 @@
 
 typedef struct {
-        mutex_t mtx;
+        SPINLOCK_DECLARE(lock);
         
         uint8_t *addr;
@@ -365 +365 @@
 {
         fb_instance_t *instance = (fb_instance_t *) dev->data;
-        mutex_lock(&instance->mtx);
+        spinlock_lock(&instance->lock);
         
         switch (ch) {
@@ -406 +406 @@
         cursor_put(instance, silent);
         
-        mutex_unlock(&instance->mtx);
+        spinlock_unlock(&instance->lock);
 }
 
@@ -473 +473 @@
         fb_instance_t *instance = (fb_instance_t *) dev->data;
         
-        mutex_lock(&instance->mtx);
+        spinlock_lock(&instance->lock);
         fb_redraw_internal(instance);
-        mutex_unlock(&instance->mtx);
+        spinlock_unlock(&instance->lock);
 }
 
@@ -554 +554 @@
         fbdev->data = instance;
         
-        mutex_initialize(&instance->mtx, MUTEX_PASSIVE);
+        spinlock_initialize(&instance->lock, "*fb.instance.lock");
         instance->rgb_conv = rgb_conv;
         instance->pixelbytes = pixelbytes;

kernel/generic/src/synch/spinlock.c

@@ -84 +84 @@
                  * This conserns especially printf_lock and the
                  * framebuffer lock.
+                 *
+                 * Any lock whose name is prefixed by "*" will be
+                 * ignored by this deadlock detection routine
+                 * as this might cause an infinite recursion.
+                 * We trust our code that there is no possible deadlock
+                 * caused by these locks (except when an exception
+                 * is triggered for instance by printf()).
+                 *
+                 * We encountered false positives caused by very
+                 * slow framebuffer interaction (especially when
+                 * run in a simulator) that caused problems with both
+                 * printf_lock and the framebuffer lock.
                  */
+                if (lock->name[0] == '*')
+                        continue;
+                
                 if (i++ > DEADLOCK_THRESHOLD) {
                         printf("cpu%u: looping on spinlock %p:%s, "