Changeset 3869c596 in mainline for uspace/drv/bus/isa/i8237.c

Timestamp:

2012-08-30T18:15:10Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

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

Children:

57b28f9

Parents:

f3fb83a

Message:

isa dma: Use size_t to transfer remaining buffer size.

Be more careful with dma size bit magic.

File:

• uspace/drv/bus/isa/i8237.c (modified) (3 diffs)

uspace/drv/bus/isa/i8237.c

@@ -38 +38 @@
 #include <bool.h>
 #include <errno.h>
+#include <ddi.h>
+#include <ddf/log.h>
 #include <fibril_synch.h>
-#include <ddi.h>
 #include <libarch/ddi.h>
-#include <ddf/log.h>
 #include "i8237.h"
 
@@ -454 +454 @@
  * @return Error code.
  */
-int dma_channel_remain(unsigned channel, uint16_t *size)
+int dma_channel_remain(unsigned channel, size_t *size)
 {
         assert(size);
@@ -484 +484 @@
         fibril_mutex_unlock(&guard);
 
-        const int remain = (value_high << 8 | value_low) + 1;
-        /* 16 bit DMA size is in words */
-        *size =  is_dma16(channel) ? remain << 1 : remain;
+        uint16_t remain = (value_high << 8 | value_low) ;
+        /* 16 bit DMA size is in words,
+         * the upper bits are bogus for 16bit transfers so we need to get
+         * rid of them. Using limited type works well.*/
+        if (is_dma16(channel))
+                remain <<= 1;
+        *size =  is_dma16(channel) ? remain + 2: remain + 1;
         return EOK;
 }