Changeset 1b93658 in mainline

Timestamp:

2011-11-14T11:08:19Z (13 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

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

Children:

c885a21

Parents:

85c4cc45

Message:

isa: Add mutex to guard access to DMA controller.

File:

• uspace/drv/bus/isa/dma_controller.c (modified) (4 diffs)

uspace/drv/bus/isa/dma_controller.c

@@ -35 +35 @@
 #include <bool.h>
 #include <errno.h>
+#include <fibril_synch.h>
 #include <ddi.h> /* pio_enable */
 #include <libarch/ddi.h> /* pio_write */
@@ -265 +266 @@
                 return EINVAL;
 
+        static fibril_mutex_t guard = FIBRIL_MUTEX_INITIALIZER(guard);
+
+        fibril_mutex_lock(&guard);
+
         if (!controller_8237.initialized)
                 dma_controller_init(&controller_8237);
 
-        if (!controller_8237.initialized)
+        if (!controller_8237.initialized) {
+                fibril_mutex_unlock(&guard);
                 return EIO;
+        }
 
         /* 16 bit transfers are a bit special */
@@ -275 +282 @@
         if (channel > 4) {
                 /* Size must be aligned to 16 bits */
-                if ((size & 1) != 0)
+                if ((size & 1) != 0) {
+                        fibril_mutex_unlock(&guard);
                         return EINVAL;
+                }
                 size >>= 1;
                 /* Address is fun: lower 16bits need to be shifted by 1 */
@@ -339 +348 @@
         pio_write_8(dma_channel.single_mask_address, value);
 
+        fibril_mutex_unlock(&guard);
+
         return EOK;
 }