ATA devices are now asynchronous. The ATA layer itself now performs the

async_wait(), though we may wish to move this higher up the stack, and
consider making the block device model asynchronous.  (There is only a
marginal cost for synchronous devices, since they can simply call
async_done() before returning; async_wait() will work seamlessly in this
situation).

src/drivers/block/ata.c

@@ -20,6 +20,7 @@
 #include <string.h>
 #include <assert.h>
 #include <byteswap.h>
+#include <gpxe/async.h>
 #include <gpxe/blockdev.h>
 #include <gpxe/ata.h>
 
@@ -48,7 +49,7 @@ ata_command ( struct ata_device *ata, struct ata_command *command ) {
 	      ( unsigned long long ) command->cb.lba.native,
 	      command->cb.count.native );
 
-	return ata->command ( ata, command );	
+	return async_wait ( ata->command ( ata, command ) );
 }
 
 /**