From 4382c68b3f1fbecb7bf731f02909bee09ec52102 Mon Sep 17 00:00:00 2001
From: Linus Nielsen Feltzing <linus@haxx.se>
Date: Sat, 9 Nov 2002 09:23:43 +0000
Subject: Greg's improved fat_cache_sector() function, now updates the second
 FAT

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2814 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/drivers/fat.c | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index 860e47df00..47bfd1afef 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -392,40 +392,50 @@ static void *cache_fat_sector(int fatsector)
 {
     int secnum = fatsector + fat_bpb.bpb_rsvdseccnt;
     int cache_index = secnum & FAT_CACHE_MASK;
+    struct fat_cache_entry *fce = &fat_cache[cache_index];
+    unsigned char *sectorbuf = &fat_cache_sectors[cache_index][0];
 
     /* Delete the cache entry if it isn't the sector we want */
-    if(fat_cache[cache_index].inuse &&
-       fat_cache[cache_index].secnum != secnum)
+    if(fce->inuse && fce->secnum != secnum)
     {
         /* Write back if it is dirty */
-        if(fat_cache[cache_index].dirty)
+        if(fce->dirty)
         {
-            if(ata_write_sectors(fat_cache[cache_index].secnum +
-                                 fat_bpb.startsector, 1,
-                                 fat_cache_sectors[cache_index]))
+            if(ata_write_sectors(fce->secnum+fat_bpb.startsector, 1,
+                                 sectorbuf))
             {
                 panicf("cache_fat_sector() - Could not write sector %d\n",
                        secnum);
             }
+            if(fat_bpb.bpb_numfats > 1)
+            {
+                /* Write to the second FAT */
+                if(ata_write_sectors(fce->secnum+fat_bpb.startsector+
+                                     fat_bpb.fatsize, 1, sectorbuf))
+                {
+                    panicf("cache_fat_sector() - Could not write sector %d\n",
+                           secnum + fat_bpb.fatsize);
+                }
+            }
         }
-        fat_cache[cache_index].secnum = 8; /* Normally an unused sector */
-        fat_cache[cache_index].dirty = false;
-        fat_cache[cache_index].inuse = false;
+        fce->secnum = 8; /* Normally an unused sector */
+        fce->dirty = false;
+        fce->inuse = false;
     }
-    
+
     /* Load the sector if it is not cached */
-    if(!fat_cache[cache_index].inuse)
+    if(!fce->inuse)
     {
         if(ata_read_sectors(secnum + fat_bpb.startsector,1,
-                            fat_cache_sectors[cache_index]))
+                            sectorbuf))
         {
             DEBUGF( "cache_fat_sector() - Could not read sector %d\n", secnum);
             return NULL;
         }
-        fat_cache[cache_index].inuse = true;
-        fat_cache[cache_index].secnum = secnum;
+        fce->inuse = true;
+        fce->secnum = secnum;
     }
-    return fat_cache_sectors[cache_index];
+    return sectorbuf;
 }
 
 static int find_free_cluster(int startcluster)
-- 
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