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Message-Id: <1253144325-1203-5-git-send-email-vapier@gentoo.org>
Date: Wed, 16 Sep 2009 19:38:39 -0400
From: Mike Frysinger <vapier@...too.org>
To: linux-usb@...r.kernel.org, Felipe Balbi <felipe.balbi@...ia.com>
Cc: linux-kernel@...r.kernel.org,
uclinux-dist-devel@...ckfin.uclinux.org,
Sonic Zhang <sonic.zhang@...log.com>,
Cliff Cai <cliff.cai@...log.com>
Subject: [PATCH 05/11] USB: musb: add notes for Blackfin anomalies
From: Sonic Zhang <sonic.zhang@...log.com>
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@...log.com>
Signed-off-by: Cliff Cai <cliff.cai@...log.com>
Signed-off-by: Mike Frysinger <vapier@...too.org>
---
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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