[PATCH 05/11] USB: musb: add notes for Blackfin anomalies

[Mike Frysinger]

From: Sonic Zhang <sonic.zhang@xxxxxxxxxx>

Add some helpful notes about how the driver works around different
anomalies that exist in the on-chip host controller.

Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
Signed-off-by: Cliff Cai <cliff.cai@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
---
 drivers/usb/musb/blackfin.h |   29 +++++++++++++++++++++++++++++
 1 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/musb/blackfin.h b/drivers/usb/musb/blackfin.h
index a240c1e..de62962 100644
--- a/drivers/usb/musb/blackfin.h
+++ b/drivers/usb/musb/blackfin.h
@@ -14,6 +14,35 @@
  * Blackfin specific definitions
  */
 
+/* Anomalies notes:
+ *
+ *  05000450 - USB DMA Mode 1 Short Packet Data Corruption:
+ *             MUSB driver is designed to transfer buffer of N * maxpacket size
+ *             in DMA mode 1 and leave rest data to the next transfer in DMA
+ *             mode 0, so we never transmit a short packet in DMA mode 1.
+ *
+ *  05000463 - This anomaly doesn't affect this driver,Since it
+ *             never uses L1 or L2 memory as data destination.
+ *
+ *  05000464 - This anomaly doesn't affect this driver,Since it
+ *             never uses L1 or L2 memory as data source.
+ *
+ *  05000465 - Actually,the anomaly still can be seen when SCLK
+ *             is over 100 MHz,and there is no way to workaround
+ *             for bulk endpoints,because the wMaxPackSize of bulk
+ *             is less than or equal to 512,while the fifo size of
+ *             endpoint 5,6,7 is 1024,the double buffer mode is
+ *             enabled automatically when these endpoints are used
+ *             for bulk OUT.
+ *
+ *  05000466 - This anomaly doesn't affect this driver,Since it
+ *             never mixs concurrent DMA and core accesses to the
+ *             TX endpoint FIFOs.
+ *
+ *  05000467 - The workaround for this anomaly will introduce another
+ *             anomaly - 05000465.
+ */
+
 #undef DUMP_FIFO_DATA
 #ifdef DUMP_FIFO_DATA
 static void dump_fifo_data(u8 *buf, u16 len)
-- 
1.6.5.rc1

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