Add a complete priority inheritance implementation to the scheduler (all mutex ownership and queue_send calls are inheritable). Priorities are differential so that dispatch depends on the runnable range of priorities. Codec priority can therefore be raised in small steps (pcmbuf updated to enable). Simplify the kernel functions to ease implementation and use the same kernel.c for both sim and target (I'm tired of maintaining two ;_). 1) Not sure if a minor audio break at first buffering issue will exist on large-sector disks (the main mutex speed issue was genuinely resolved earlier). At this point it's best dealt with at the buffering level. It seems a larger filechunk could be used again. 2) Perhaps 64-bit sims will have some minor issues (finicky) but a backroll of the code of concern there is a 5-minute job. All kernel objects become incompatible so a full rebuild and update is needed.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16791 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 6 insertions, 0 deletions

diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index 8ae3b70cd3..a538b92695 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -259,6 +259,12 @@ void fat_init(void)
         mutex_init(&cache_mutex);
     }
 
+#ifdef HAVE_PRIORITY_SCHEDULING
+    /* Disable this because it is dangerous due to the assumption that
+     * mutex_unlock won't yield */
+    mutex_set_preempt(&cache_mutex, false);
+#endif
+
     /* mark the FAT cache as unused */
     for(i = 0;i < FAT_CACHE_SIZE;i++)
     {