devmdv: fix open/close handling

diff --git a/Kernel/platform-zx128/devmdv.c b/Kernel/platform-zx128/devmdv.c
index db9f1be..3fd7cd6 100644 (file)
--- a/Kernel/platform-zx128/devmdv.c
+++ b/Kernel/platform-zx128/devmdv.c
@@ -14,7 +14,7 @@
 
 /* Should probably have a max and a max open to keep the maps managable */
 static unsigned char mdvmap[MAX_MDV][256];
-static uint8_t mdv_valid;
+static uint8_t mdv_count[MAX_MDV];
 
 /* Used by the asm helpers */
 uint8_t *mdv_buf;
@@ -126,33 +126,35 @@ int mdv_open(uint8_t minor, uint16_t flag)
                udata.u_error = ENODEV;
                return -1;
        }
-       mdv_motor_on(minor + 1);
-       t = tmpbuf();
-       mdv_buf = t;
-       mdv_sector = 1;
-       mdv_page = 0;
-       err = mdv_bread();
-       if (err) {
-               mdv_sector = 128;
+       if (!mdv_count[minor]) {
+               mdv_motor_on(minor + 1);
+               t = tmpbuf();
+               mdv_buf = t;
+               mdv_sector = 1;
+               mdv_page = 0;
                err = mdv_bread();
                if (err) {
-                       kprintf("mdv_open: maps bad: %d\n", err);
-                       mdv_motor_off();
-                       udata.u_error = ENXIO;
-                       return -1;
+                       mdv_sector = 128;
+                       err = mdv_bread();
+                       if (err) {
+                               kprintf("mdv_open: maps bad: %d\n", err);
+                               mdv_motor_off();
+                               udata.u_error = ENXIO;
+                               return -1;
+                       }
+                       kprintf("mdv_open: had to use secondary map\n");
                }
-               kprintf("mdv_open: had to use secondary map\n");
+               memcpy(mdvmap[minor], t, 256);
+               brelse(t);
+               mdv_motor_off();
        }
-       memcpy(mdvmap[minor], t, 256);
-       brelse(t);      
-       mdv_valid |= 1 << minor;
-       mdv_motor_off();
+       mdv_count[minor]++;
        return 0;
 }
 
 int mdv_close(uint8_t minor)
 {
        /* Simple approach for now */
-       mdv_valid &= ~(1 << minor);     
+       mdv_count[minor]--;
        return 0;
 }