[alsa-devel] [PATCH] [26/29] ALSA: dice: document quadlet alignment

Clemens Ladisch clemens at ladisch.de
Mon Oct 21 21:35:25 CEST 2013


Doing accesses without quadlet alignment is a bad idea because the
firmware's byte-swapping would garble the data; clarify this in the
documentation.

Signed-off-by: Clemens Ladisch <clemens at ladisch.de>
---
 sound/firewire/dice-interface.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/firewire/dice-interface.h b/sound/firewire/dice-interface.h
index af916b9..27b044f 100644
--- a/sound/firewire/dice-interface.h
+++ b/sound/firewire/dice-interface.h
@@ -7,9 +7,9 @@

 /*
  * Generally, all registers can be read like memory, i.e., with quadlet read or
- * block read transactions with any alignment or length.  Writes are not
- * allowed except where noted; quadlet-sized registers must be written with
- * a quadlet write transaction.
+ * block read transactions with at least quadlet-aligned offset and length.
+ * Writes are not allowed except where noted; quadlet-sized registers must be
+ * written with a quadlet write transaction.
  *
  * All values are in big endian.  The DICE firmware runs on a little-endian CPU
  * and just byte-swaps _all_ quadlets on the bus, so values without endianness


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